VENOMS VENOMOUS ANIMALS AND ANTIVENOMOUS SERUM - THERAPEUTICS BY A. CALMETTE, M.D., CORRESPONDING MEMBER OF THE FRENCH INSTITUTE AND OF THE ACADEMY OF MEDICINE, DIRECTOR OF THE PASTEUR INSTITUTE, LILLE TRANSLATED BY ERNEST E. AUSTEN, F.Z.S. LONDON JOHN BALE, SONS & DANIELSSON, LTD. 83-91, GREAT TITCHFIELD ST., OXFORD ST., W. 1908 ALL RIGHTS RESERVED i PHEFACE TO ENGLISH EDITION. Mr. E. E. Austen, of the British Museum, has been good enough to undertake the translation of my book on "Venoms." For the presentation of my work to the scientific pubhc in an Engiisli dress I could not have hoped to find a more faithful interpreter. To him I express my livehest gratitude for the trouble that he has so kindly taken, and I thank Messrs. John Bale, Sons and Danielsson for the care they have bestowed upon the preparation of this edition. Institut Pasteur cle Lille, A. Calmette, M.D. June 17, 1908. I I INTRODUCTION TO FRENCH EDITION. In the montli of October, 1891, during the rains, a village in the vicinity of Bac-Lieu, in Lower Cochin-China, M'as invaded by a swarm of poisonous snakes belonging to the species known as Naja tripudians, or Cobra-di-Capello. These creatures, which were forced by the deluge to enter the native huts, bit four persons, who succumbed in a few hours. An Annamese, a professional snake-charmer in the district, succeeded in catching nineteen of these cobras and shutting them up ahve in a barrel. M. Seville, the admin- istrator of the district, thereupon conceived the idea of forwarding the snakes to the newly established Pasteur Institute at Saigon, to which I had been appointed as director. At this period our knowledge of the physiological action of venoms was extremely limited. A few of their properties alone had been brought to light by the works of Weir Mitchell and Reichard in America, of Wall and Armstrong in India and England, of A. Gautier and Kaufmann in France, and especially by Sir Joseph Fayrer's splendidly illustrated volume (" The Thanatophidia of India "), pub- lished in London in 1872. An excellent opportunity was thus afforded to me of vi. INTEODUCTION TO FRENCH EDITION taking up a study which appeared to possess considerable interest on the morrow of the discoveries of E. Eoux and Behring, with reference to the toxins of diphtheria and tetanus, and I could not allow the chance to escape. For the last fifteen years I have been occupied continuously with this subject, and I have published, or caused to be published by my students, in French, English, or German scientific journals, a fairly large number of memoirs either on venoms and the divers venomous animals, or on anti- venomous serum-therapeutics. The collation of these papers is now becoming a matter of some difficulty, and it appeared to me that the time had arrived for the production of a monograph, which may, I hope, be of some service to all who are engaged in biological research. Antivenomous serum-therapy^ which my studies, sup- plemented by those of Phisalix and Bertrand, Fraser, George Lamb, F. Tidswell, McFarland, and Yital Brazil, have enabled me to establish upon scientific bases, has now entered into current medical practice. In each of the countries in which venomous bites represent an important cause of mortality in the case of human beings and domestic animals, special laboratories have been ofiicially organised for the preparation of anti-venomous serum. All that remains to be done is to teach its use to those who are ignorant of it, especially to the indigenous inhabitants of tropical countries, where snakes are more especially formid- able and deadly. This book will not reach such people as these, but the medical men, naturalists, travellers, and explorers to whom it is addressed will know how to popu- larise and apply the information that it will give them. INTBODUCTION TO FBENCH EDITION vii. I firmly, believe also that physiologists will read the book with profit. Its perusal will perhaps suggest to them the task of investigating a host of questions, which are still obscure, relating to toxins, their mode of action upon the different organisms, and their relations to the antitoxins. There is no doubt that in the study of venoms a multitude of workers will, for a long time to come, find material for the exercise of their powers of research. At the moment of completing this work I would like to be allowed to cast a backward glance upon the stage that it marks in my scientific career, and to express my heart- felt gratitude to my very dear master and friend, Dr. Emile Eoux, to whom I owe the extreme gratification of having been able to dedicate my life to the study of experimental science, and of having caused to germinate, grow, and ripen a few of the ever fertile seeds that he sows broad- cast around him. I am especially grateful to those of my pupils, C. Guerin, A. Delearde, F. Noc, L. Massol, Bernard, and A. Briot, who have helped me in my work, while showering upon me the marks of their confidence, esteem, and attachment ; to my former chiefs, colleagues, and friends of the Colonial Medical Staff, Drs. G. Treille, Kermorgant, Paul Gouzien, Pineau, Camail, Angler, Lepinay, Lecorre, Gries, Lhomme, and Mirville; and to my numerous foreign or French corre- spondents, George Lamb, Semple, C. J. Martin, Vital Brazil, Arnold, de Castro, Simon Flexner, Noguchi, P. Kyes, Morgenroth, J. Claine, Piotbey, and E. P. Travers, several of whom have come to work in my laboratory, or have obligingly procured for me venoms and venomous animals. viii. INTRODUCTION TO FBENCH EDITION I have experienced at the hands of a large number of our mmisters, consuls, or consular agents abroad the most cordial reception on repeatedly addressing myself to them in order to obtain the papers or information of which I was in need. It is only right for me to thank them for it, and to acknowledge the trouble that M. Masson has most kindly taken in publishing this book. Institut Pasteur de Lille; March 10, 1907. A. Calmette. TABLE OF CONTENTS. PAET I. Page Chap. I. — I. General notes on poisonous animals 1 II. General classification of poisonous snakes. Their anatomo- physiological characters ... ... ... ... .•• 3 Chap. II. — Habits of poisonous snakes. Their capture 17 Chap. III. — Description of the principal species of poisonous snakes. Their geogi-aphical distribution ... ... ... ... ••• 22 A. Europe ... ... ... ... ■■■ ■■■ ■■■ 22 B. Asia, Dtdch Indies and Pliilijppine Islands ... 30 C. Africa 57 D. Australia and adjacent large islands ... ... 81 E. Ame7'ica ... ... ... ••• ■•• ••• ••• 100 F. HydrophiidcB (sea-snakes) ... 131 G. Geog7-a]jliical distribution of the in-incipal genera of poisonous snakes in the five divisions of the zvorld ... ... ... •■• ••• ••• ••■ 142 PART II. Chap. IV.— Secretion and collection of venom in snakes 147 Chap. V. — Chemical study of snake-venoms ... 1^9 Chap. VI. — Physiological action of snake-venoms ... 168 A. Physiology of poisoning in man and in animals bitten by the different species of poisonous snakes {Colu- hridcB, Viperidce, Hydroqihiidce) 168 B. Physiology of experimental poisoning 170 C. Determination of the lethal doses of venom for dif- ferent species of animals 173 D. Effects of venom in non-lethal doses 177 X. TABLE OF CONTENTS Chap. VII. — Physiology of poisoning (continued). Effects of the various venoms on the different tissues of the organism 179 (1) Action upon the liver ... ... ... ... ... 182 (2) Action upon the kidney 183 (3) Action upon the spleen, heart and lungs 183 (4) Action upon the striated muscles ... 184 (5) Action upon the nervous centres 185^ Chap. VIII. — Physiology of poisoning {continued). Action of venoms on — -\ the blood 188 \ A. Effects of venom on the coagulation of the blood ... 188 I. Coagulant venoms ... ... 190 II. Anticoagulant venoms ... ... ... ... 192 III. Mechanism of the anticoagulant action of venoms on the blood ... ... ... 195 B. Effects of venom on the red corpuscles and on the serum ... ... ... ... ... 196 (1) Haemolysis 196 (2) Precipitins of venoms ... ... 202 (3) Agglutinins of venou.s ... ... ... ... 202 C. Effects of venom upon the white corpuscles : Leuco- lysin 208 -J Chap. IX. — Physiology of poisoning {continued). Proteolytic, cytolytic, bacteriolytic, and various diastasic actions of venoms : diastasic and cellular actions on venoms ... 204 | A. Proteolytic action... ... ... 204 B. Cytolytic action ... ... ... ... 206 C. Bacteriolytic action ... 206 D. Various diastasic actions of venoms 212 E. Action of various diastases upon venoms ... ... 214 Chap. X. — Toxicitv of the blood of venomous snakes 217 Chap. XI. — Natural innnunity of certain animals with respect to snake- venoms ... ... ... ... ' ... 222 Chap. XII. — Snake-charmers TABLE OF CONTENTS xi. PAET III. ANTIVENOMOUS SEKUM-THERAPBUTIOS. Chap. XIII. — Vaccination against snake-venom — Preparation of anti- ' venomous serum — Its preventive properties as regards intoxication by venom ... ... ... ... ... ... 241 Specificity and poly valence of antivenomous serums ... 248 Chap. XIV. — Neutralisation of venom by antitoxin 253 Chap. XV. — Treatment of poisonous snake-bites in man and animals. Objects of the treatment. Technique of antivenomous serum-therapy ... ... ... ... ... ... .. 259 PART IV. VENOMS IN THE ANIMAL SERIES Chap. XVI. — Venoms in the animal series. 1. — Invertebrates ... A. Coelenterates B. Echinoderms C. Arthrojiods : (a) Araneids — {b) Scorpions — (c) Mijriopods — {d) Insects D. Molluscs ... 269 269 273 274 276. 280 281 286 Chap. XVII.— Venoms in the. animal series {continued). 2J- — Venomous fishes A. Teleostei. Acantlioptei-yfjii . B. Teleostei. C. Teleostei. Plectognathi. Fhysostomi : TriglidcB ... Trachinidee GobiidcB ... Teuthididce Batrachiidcc 6. Pediculati, 1. Siluridce ... 2. Murcenidce 288 290 297 300 301 302 303 305 307 308 309 TABLE OF CONTENTS Chap. XVIII. — Venoms in the animal series {continued). 3. — Batrachians ; Lizards ; Mammals 312 A. Batrachians ... ... ... ... 312 B. Lizards ... ... ... 321 C. Mammals {Omithorhynchua) ... ... 323 PART V. DOCUMENTS. I. — A few notes and observations relating to bites of i^oisonous snakes treated by antivenomous serum-therapeutics ... 326 II- — ^ feio notes and observations relating to domestic animals bitten by poisonous snakes and treated tvith serum 3,56 III. — Note on the collection of cobra-venom and the treatment of poisonous bites in the French Settlements in India {by Dr. Paul Gouzien) ... 359 LIST OF ILLUSTHATIONS- Yig. 1. — A. Skull of one of the non-poisonous Colubridce (Ptyas mucosus) 7 B. Skull of one of the j)oisonous Colubridce {Naja trijmdians) 7 c. Skull of one of the poisonous ColubridcB {Bwngarus fasciatus) 7 D. Skull of one of the Viperidce {Viioera russellii) 7 E. ^\ux\\ oi one ot ihe Vii:ieridcB CrotalincB {CroiahLS durissiis) ... 1 F. Skull of one of the Coluhridm HydropliiincB [HydropJiis ijelmnis) 7 Fig. 2. — A. Maxillary bone and fangs of one of the Vijperido} {Viper a russellii) ... ... ... ... ... ... ••■ ... 8 B. Maxillary bone and fangs of one of the ColubridcB {Naja tripu- clians) ... ... ... ... ... ... ••• ••• 8 c. Maxillary bone and fangs of one of the Colubridce {Bungarus fasciatus) ... ... ... ... .-• ... ... .-■ 8 D. Maxillary bone and teeth of one of the non- poisonous Colu- bridce {Ptyas mucoszis) ... ... ... ... ... ... 8 Fig. 3. — A. Fang of one of the Viperidce {Vipora russellii) 8 D. Transverse section of the fang ... ... ... ... ... 8 Fig. 4. — B. 'Fesag oi one at ColubridcB {Naja tripudians) 9 E. Transverse section ... ... ... ... ... ... ... 9 Fig. 5. — c. Fang of one of the Hydrophiince {Hydropliis pelamis) 9 F. Transverse section ... ... ... ... ... ... ..- 9 Fig. 6. — Three transverse sections of a poison-fang of one of the Colubridce 9 Fig. 7. — Marks produced on the skin by the bites of different species of snakes ... ... ... ... ... •.• ... •■• 10 Fig. 8. — Poison-gland and fangs of a venomous snake {Naja tripudians) . . . 11 Fig. 9. — Muscular apparatus and poison-gland of Vipera russellii ... 12 Fig. 10. — Muscular apparatus and poison-gland of Fi^jera ritssellii ... 12 Fig. 11. — Muscular apparatus and poison-gland of Naja tripudia.ns ... 13 Fig. 12. — Muscular apparatus and poison-gland of Naja trijnidians ... 13 Fig. 13. — Arrangement of the scales of the head in one of the non-poisonous Cohibridce {Ptyas mucosus) ... ... ... ... ... 14 Fig. 14.— Arrangement of the scales of the head in one of the poisonous Cohibridce {Naja tripudians) 15 Fig. 15. — Feeding a poisonous snake (first stage) 18 Fig. 16. — Feeding a poisonous snake (second stage) 18 xiv. LIST OF ILLUSTliATIONS 19 20 21 23 Fig. 17.— Capture of a Naja tripudiana (first stage) Fig. 18. — Capture of a Naja tripudiana (second stage) Fig. 19. — Hindn carrying two captured Cobras in " chatties " Fig. 20.— Maxillary bone, mandible, and head of Cailopeltis monapessulana Fig. 21.— (1) Vipera berus ; (2) Vipera. aspis ; (3) Vipera ammodytcH ■ (4) Vipera ammodi/tci ... ... ... _ " ' Fig. 22. — Fipem rts^is, from the Forest of Fontainebleau Fig. 23. — Skull oi Buriffarus Fig. 24. — Bungarus fasciatus (India) Fig. 25. — SkvAl oi Naja tripudians Fig. 2Q.—Naja trijmdians (Cobra-di-Capello) on the defensive, preparing to strike Fig. 27. — Naja tripudians (Cobra-di-Capello) Fig. 28. — Vipera russellii (Daboia) Fig. 29.— Psendocerastes jiersicus ... ... ... ' Fig. 30. — Echis carinatus (India) Fig. 31. — Ancistrodon hyjmale {Ciiva.'wallsL, oi Ceylon) Fig. 32. — Lachesis oMnavensis Fig. 33. — Lachesis flavovbaculatus Fig. 34. — S^mII Dendraspiis viridis Fig. 35. — Slmll oi Causus rliovibeatus ... Fig. 36.— Skull of Bitis arietans (Puff Adder) Fig. 37. — Bitis arietans (Puff Adder) Fig. 38. — Bitis cornuta Fig. 39. — Bitis rasicornis ... Fig. 40. — Cerastes cornutus Fig. 41. — Echis coloratus... Fig. 42. — Skull of Atractasjns aterrima, Fig. 43.— Skull of Glyphodon tristis (Australian Colubrine) Fig. 44. — Pseudelaps hrefftii ... ... ... ... . . gg Fig. 45. — Pseudelaps harriettcB ... ... ... ... gg Fig. 46. — Pseudelaps diadema ... ... ... ... gg Fig. 47. — Diemenia psammophis ... ... ... ... gg Fig. 48. — Diemenia olivacea Fig. 49. — Diemenia textilis Fig. 50. — Diemenia nuchalis Fig. 51. — Pseudeohis porphyriacus (Black Snake) 87 Fig. 52. — Denisonia superha (Copperhead) 89 Fig. 53. — Denisonia coronoides ... Fig. 54. — Denisonia ramsayi Fig. 55. — Denisonia signata Fig. 56. — Denisonia maculata ... ... ... gj Fig. 57. — Denisonia gouldii ... ... ... Fig. 58. — Hoplocephalus bitorquatus 94 Fig. 59. — Notechis scutaius (Tiger Snake) 95 Fig. 60.— Skull of Acanthophis antarcticiis (Death Adder) 95 25 28 31 32 34 35 36 45 47 48 50 52 55 65 68 70 71 73 74 75 77 79 83 86 86 87 89 90 90 LIST OF ILLUSTRATIONS xv. I'AUE Fig. 61. — AcanthopMs antarcticus 97 Fig. 62. — Bhynchelaps australin 98 Fig. 63.— Skull of Ficrina occipitalis 99 Fig. 64. — Fiorina occipitalis ... ... ... ... ••• ... .•• 99 Fig. 65.— Skull of Flaps marcgravii 101 Fig. 66. — Flaps f iilvius (Harlequin Snake) 105 Fig. 67.— Head and Skull of Crotalus horridus (Horrid Rattle-snake) ... 109 Fig. 68. — Ancistrodon piscivorus (Water Viper) 110 Fig. 69. — Lachesis lanceolatus (Fer-de-Lance) .. 112 Fig. 70. — Lachesis neuiviedii (Urutii) ... 116 ■pig, 71. — Sistrurus catenatus (Prairie Rattle-snake) 121 Fig. 72. A. Horny appendage (rattle) of a Crotalus horridus 122 B. Horny appendage, longitudinal section ... 122 C. Separated segments of the appendage 122 Fig. IQ.—GrotakLs terrificus (Dog-faced Rattle-snake) 123 Fig. 74. — Crotalus scutulatus (Texas Rattle-snake) 126 Fig. 15.—Crotalu.s confluentus (Pacific Rattle-snake) 128 Pig, 76. — Crotalus cera.stes (Horned Rattle-snake) 130 Fig. 77. — Skull of Hydrus platurus 132 Fig. 78. — Hydrus plattirus 133 Fig. 79. — HydropMs coronatus 134 Fig. QQ.— HydropMs elegans 135 Fig. 81.— Skull of Distira 137 -pig, 82. — Enhydrina valakadien (E. bengalensis) 138 Fig. 83. — Skull of Plattorus coluhrinus 139 Fig. 84. — Platurus laticaudatus (P. fischeri) 140 Fig. 85. — Collecting venom from a Lachesis at the Serotherapeutic Insti- tute of Sao Paulo (Brazil) 154 Fig. 86.— Chloroforming a Cobra in order to collect venom at Pondicherry (first stage) 155 Fig. 87.— Chloroforming a Cobra in order to collect venom at Pondicherry (second stage) ... ... ••. ••• ••• •■• ••• 157 Fig. 88.— Collecting Cobra-venom at Pondicherry (third stage) 158 Fig. 89. — Mongoose seized by a Cobra 225 Fig. 90.— Indian Snake-charmer at Colombo (Ceylon) 230 Yig. 91.— Indian Snake-charmer at Colombo (Ceylon) 231 Fig. 92.— Musical instrument used by Indian snake-charmers to charm Cobras ••• ^32 Fio-. 93.— Vaccinating a horse against venom at the Pasteur Institute, LiUe 244 Fig. 94.— Aseptically bleeding a horse, vaccinated against venom, in order to obtain antivenomous serum, at the Pasteur Institute, Lille... 245 Fig. 95. Technique of injecting antivenomous serum beneath the skin of the abdomen Fig. 96. — Lactrodectus mactans 275 Fig. 97. — Scorpio occitanus ... ... ... .•■ ••• ••• ••• 277 Fig. 98. — Scolopendra morsitans 280 LIST OP ILLUSTRATIONS Fig. 99.— Poison-apparatus of the bee Fig. lOO.-Intei-ior of the gorget of the Bee ^E- '^Ol.—Sijnmiceia hrachio vav. Verrucosa It Jo?'~?°'"'' ''■"'•^^^"^(Sea Scorpion, or Father Lasher')" ' Fig. 104:.~Scorpana diabolus ... .. Fig. 105.— Pterois arteinata Fig. lO&.—Pelor filamentosum Fig. 107.— Trac/amis w>.e7-« (Lesser Weaver j Fi¥ !oQ"~r^r"^ ■ ™ 'P'"*^ °^ ^^^''^ Lesser We'ever ' -fig. 109.~Calhonyimis lyra (Dragonet) ccvei .. Fig. 110. — Batrachus grunniens ... "' Fig. lll.—Thalassoplirync reticulata ... Fig. 112. — Lophius setigeriis Fig. ll'^.—Serranus ouatahili ' ' Fig. 114. — Holacantlms imjjerator Fig. 115.~Tetrodon steUatus ... ... "' Fig. 116. — Tetrodon ruhripes Fig. in.—CMlomycterus orbiciilaris Fig. 118.— Chilomyctorus tigrinus ... Fig. 119.— Silurus glands ... ... ... Fig. 120. — Murcena moringa ... Z'^' J21--^ai««ifin^?m maculosa (Spotted Salamander) -tig. lll.—TrUon viarmoratus (Marbled Newt) Fi> }ll-^f''"^^''^f^^^ japonicus (Great Japanese Salamande^i -fig. i^4. — Heloderma liomdum Fig. I'i^.-Ornithorhynchus paradoxus '(Duck-billed Platypus) VENOMS. PART T. CHAPTEE 1. GENEBAL NOTES ON POISONOUS ANIMALS— POISON- OUS SNAKES: GENERAL CLASSIFICATION AND ANATOMO-PHYSIOLOGICAL CHABACTEBS. I. — General Notes on Poisonous Animals. A LARGE number of animals possess special glandular organs capable of secreting toxic substances called venoms. Sometimes these substances are simply discharged into the surrounding medium, and serve to keep off enemies {toad, sala- mander) ; sometimes they mingle with the fluids and digestive juices, and then play an important part in the nourishment of the animal that produces them (snakes) ; in other cases, again, they are capable of being inoculated by means of stings or teetJi specially adapted for this purpose, and then they serve at once as a means of attack or defence, and as a digestive ferment {snakes, spiders, scorpions, bees). An animal is said to be venomous when it possesses the power of inoculating its venom. Venomous species are met with in almost all the lower zoological groups, in the Protozoa, Coelenterates, Arthropods, Molluscs, and in a large number of Vertebrates (fishes, amphibians, and reptiles). The reptiles are best endowed in this respect, and it is in this class of creatures that we meet with the species most dangerous 1 2 VENOMS to man and to mammals in general. The study of their venom, too, is of considerable interest, since it should lead to the quest of means of protection sufficiently efficacious to preserve us from their attacks. Venomous reptiles are not always easy to distinguish from those devoid of any inoculatory apparatus. For this reason both classes alike have at all times inspired mankind with a lively dread, which is displayed among the various races in legends and religious beliefs. In ancient days the cult of the snake occupied a prominent place. In Genesis the serpent is the incarnation of the Evil One, tempting and deceitful. In Greece it was the symbol of wisdom and prudence. In Egypt it was associated with the Sacred Scarabseus and the flowers of the lotus to represent Immortality ! At Kome epidemics ceased when the snake sacred to ^scu- lapius was brought from Epidaurus. According to Kraff, the Gallas of Central Africa consider the snake as the ancestor of the human race, and hold it in great respect. In India the cult of the Seven-headed Naja, or serpent-god, was formerly almost as flourishing as that of Buddha. It is still regarded as a crime to kill a Cobra when it enters a hut ; prayers are addressed and food is offered to it. Its presence is an omen of happiness and prosperity ; it is believed that its death would bring down the most terrible calamities on whomsoever should have brought it about, and on his family. Nevertheless, in the Indian Peninsula alone, the Cobra, the Kxait, and a few other extremely poisonous species of snakes cause every year an average of 25,000 deaths. The number of fatalities from the same cause is likewise considerable in Burma, Indo- China, the Dutch Indies, Australia, Africa, the West Indies and Tropical America generally. The temperate regions of the globe are less severely affected ; GENERAL CLASSIFICATION OF POISONOUS SNAKES 3 but in North America the Kattlesnake and the Moccassin are especially deadly. In France the Common Viper abounds in Jura, Isere, Ardeche, Auvergne, Vendee, and the Forest of Fontainebleau. Three hundred thousand have been killed in twenty-seven years in the Department of Haute-Saone alone. Every year this snake causes the death of some sixty persons. Cow-herds, shepherds, and sportsmen fear: it greatly, since it is very dangerous to cattle, sheep, and dogs. II. — Genbkal Classification of Poisonous Snakes. Their Anatomo-physiological Characters. Poisonous snakes are divided by naturalists into two great Families, the CoLUBRiDiE and Viperid^, distinguished from each other by certain anatomical characters, and especially by the dentition. The CoLUBRiD^ resemble harmless snakes, which renders them all the more dangerous. They are divided into two groups : Opisthoglypha {oinaOev, behind ; jXucpr}, a groove) and Proterogltpha {Trporepov, before ; ^\v(^7], a groove). The Opisthoglypha have the upper jaws furnished in front with smooth or non-grooved teeth, but behind with one or several rows of long, canaliculate teeth. This group includes three Sub-families : — A. The Hovialopsince, having valved nostrils, placed above the snout. B. The Bipsadomorphince, in which the nostrils are lateral in position, and the dentition is highly developed. C. The Elachistodontinai, which have but rudimentary teeth only on the posterior portion of the maxillary, on the palatine and on the pterygoid bones. Almost all the snakes belonging to these three sub-families are 4 VENOMS poisonous, but only slightly so. They are not dangerous to man. Their venom merely serves to paralyse their prey before deglutition takes place ; it does not afford them an effective means of defence or attack. All the HomalopsincB are aquatic ; they bring forth their young in the water, and are met v^ith commonly in the Indian Ocean, starting from Bombay, and especially in the Bay of Bengal, on the shores of Indo-China and Southern China, from Singapore to Formosa, in the Dutch Indies, in Borneo, the Philippines, New Guinea and the Papuan Archipelago, and as far as the north of Australia. The Dipsa.clomorpimm comprise a large number of highly cosmopolitan genera and species, found in all the regions of the earth except the northerly portions of the Northern Hemisphere. None of these reptiles is capable of causing serious casualties among human beings, owing to the pecuHarly defective arrangement of their poison-apparatus. I therefore do not think it worth while to linger here over their description. The Elachistodontincp. are of even less importance ; at the present time only two species are known, both of small size and confined to Bengal. The Protbroglypha group of the Coluhridce is of much greater interest to us, since all the snakes belonging to it are armed with powerful fangs, in front of the upper maxillaries. These fangs, which are provided with a channel in the shape of a deep groove, communicate at the base with the efferent duct of poison glands, which are often of very large size. The group is composed of two Sub-families' : — A. The HijdrophiincB (sea-snakes), provided with a flattened oar-shaped tail. The body is more or less laterally compressed ; the eyes are usually small, with circular pupils ; the scales of the nose have two notches on the upper labial border. The normal habitat of all the members of this sub-family is the GENERAL CLASSIFICATION OF POISONOUS SNAKES 5 sea, near the shore, with the exception of the genus Distira, which is met with in the fresh water of a lake in the Island of Luzon, in the Philippines. They are frequently found in very large numbers in the Indian seas and throughout the tropical zone of the Pacific Ocean, from the Persian Gulf to the west coast of the American Continent, but they are entirely absent frohi the West Coast of Africa. B. The ElapioicB (land-snakes), with a cylindrical tail, and covered with smooth or carinate scales. These serpents are fre- quently adorned with brihiant colours. Some of them (belonging to the genus Naja) have the faculty of expanding the neck in the shape of a parachute, by spreading out the first pairs of ribs when they are alarmed or excited : the breadth of the neck then greatly exceeds that of the head. They are distributed throughout Africa, Asia, and North and South America, and are also found in Australia, where almost all the snakes that are known belong to this sub- family. The Family ViPEEiDiE is characterised by a triangular head, which is widened posteriorly, and by the general aspect of the body, which is usually thick-set and terminated by a short tail. The bones of the face are movable. The praefrontal bone is not in contact with the nasal ; the maxillary is greatly shortened and may be articulated perpendicularly to the ectopterygoid ; it bears a pair of large poison-fangs, one on each side, and these are always accompanied by several teeth to replace them, folded back in the gum ; these latter teeth come in succession to take the place of the principal tooth, when this is broken or falls out of itself when the snake sheds its skin. The poison-fangs are not grooced, as in the Proteroglyphous CohibridcB ; they are pierced by a perfectly formed canal, the Upper end of which inosculates with the efferent duct of the corresponding poison-gland, while its lower extremity opens to the exterior a little above and in front of the tip. The latter is always very sharp. 6 VENOMS The palate and lower jaw are furnished with small hooked teeth, which are solid and non-venomous. With the exception of the species of Atractasjns, these snakes are all ovoviviparous. The majority are terrestrial ; a few lead a semi-aquatic existence, while others are arboreal. Their distribution includes Europe, Asia, Africa (with the excep- tion of Madagascar), and North and South America. They do not exist in Australia. They are divided into two Sub-families: — A. The Viperince, in which the head, which is very broad and covered with little plates and scales, has no pit between the nose and the eyes ; B. The CrotalincB {Kporakov, a rattle), in which the head is incompletely covered with scales, and exhibits a deep pit on each side, between the eye and the nostril. Among snakes, the characters that serve as a basis for the determination of genera and species are the general shape of the body, especially that of the head, the arrangement of the cephahc scales, the .cranial skeleton, and the dentition. ■ Cranial Skeleton. — The cranium is composed of a certain number of bones, the homologues of which are found in the mammalian skeleton ; but the bones are complex, and subject to modifications according to the structure and habitat of each species. The special arrangement of the bones of the face is above all characteristic of the poisonous snakes. Those forming the upper jaw, the palate and the mandibles or " inter-maxillaries " are mov- able upon each other and on the cranium. The upper and lower maxillaries are united by an extensile ligament and articulated with the tympanic bone, which permits the niouth to be opened very widely when the animal swallows its prey. Dentition. — The non-poisonous snakes have two rows of teeth in the upper jaw — one external, the maxillary, usually composed of GENERAL CLASSIFICATION OF POISONOUS SNAKES 7 Pig 1 -A Cranial skeleton of one of the non-poisonous Colubridce (Ptyas vmcosus); B cranial skeleton of one of the poisonous Colubi-ida> (Naja tripicdians) ; c, crania skeleton of one of the poisonous Colubridcs (Bimgarns fasciatus) ; d, cranial skeleton of one of the Viparidm (Vipara russellii) ; e, cranial skeleton of one of the Viperida> CrotalincB (Crotalus durissus) ; f, cranial skeleton of one of the Colubndce Hydro- phi/inat (Hydrophis pelamis). VENOMS As. from 35—40 small, backwardly curved teeth ; the other internal, the palatine, which only numbers from 20—22 teeth, having the same curvature (fig. 1, a). In the poisonous snakes the maxillary bones are shorter, and the outer row is represented by a single long and tubular or grooved tooth (the fang), fused with the maxillary bone, which is itself mov- able (fig. 1, B, c, D, E, F). Certain species {Dip- sas) have maxillary teeth which increase in size from front to rear; the longest teeth are grooved and serve for the better retention of prey, and also to impregnate it with saliva; but they are not in communication with the poison-glands. The poison-fangs are normally covered with a fold or capsule of mucous membrane, in which they are sheathed. This fold con- ceals a whole series of reserve teeth in different degrees of development, which eventually become attached to the extremity of the maxillary when the principal tooth falls out or is broken (fig. 2). Poiso7i Apparatus. — The grooved or fur- rowed teeth in the P voter oglypha and the canaliculate teeth in the Solenoglypha are arranged, not for the purpose of seizing Pig. 2.— a, Maxillary bone and fangs of one of the Viperidcz {Vipera russellii) ; b, maxillary bone and fangs of one of the Golubridcn (Naja tripu- dians) ; c, maxillary bone and fangs of one of the ColuhridcB {Bungarus fasciatus) ; d, maxillary bone and teeth of one of the non-poisonous Colu- hridcB {Ptyas miicosus). (After Sir Joseph Fayrer.) Fig. 3.— a, Fang of one of the ViperidcB [Vipera russellii) ; d, transverse sec- tion of the fang. 1.., GENERAL CLASSIFICATION OF POISONOUS SNAKES prey, but in order to deal it a mortal blow by injecting the venom into its flesh. In the normal position they lie almost g horizontally, and exhibit no mobility of their own. But, when the animal prepares to bite, their erection is effected by the snake throwing its jaw back ; and this movement, which is always very sudden, enables it at the same time to compress its poison- glands, by the aid of special constrictor muscles. On examining the various species of poisonous snakes, we observe very sharply marked differences in the arrangement and dimensions of the teeth. Tbus, in the ViPERiD^ they are long, extraordinarily sharp, and capable of producing deep wounds (fig. 2, A, and fig. 3). Tbey are traversed by an almost completely closed canal, from the base, which communicates with the poison-duct, to the neighbourhood of the point, where it opens very obliquely on the convex surface (fig. 3, a and d). Fig. 4. — b. Fang of one of the Coluhridoi {Naja tri-pudians) ; e, transverse section. c Fig. 5. — c, Fang of one of the HydrophiincB {Hydr- ophispelamis); f, transverse section. In the ElapincB sub-family of the Colu- hridcB, and especially in the HydwpJmncB, the teeth are much shorter and simply grooved or canaliculate ; that is to say, the canal communicates with the exterior throughout its extent by a narrow slit, which traverses the entire convex surface of the tooth (figs. 4, 5, and 6). It does not follow from this that the the bites of these reptiles are less dangerous; Fig. 6. — Three transverse sections of a poison-fang of one of the Colubridce, through A A, B B, c c ; p p, pulp cavity ; v v v, poison- canal (groove). (After C. J- Martin.) 10 VENOMS the contrary, indeed, is the case, for their venom is infinitely more active. These differences, as well as the particular mode of arrangement of the other little non-poisonous teeth in both jaws, enable us in many cases to recognise, by the mere appearance of the bite, the species of snake by which the bite has been inflicted. I. II. III. Fig. 7. — Marks pboduced on the Skin by the Bites of difpebent Species op Snakes. I. Non-venomous Colubrine. — The bite is marked only by the imprint of from 35—40 small palatine or pterygoid teeth, and 20—22 upper maxillary teeth (on the outside of the foregoing) on each side. II. Venomous Colubrine {Naja tripudians, Peoteroglypha). — The bite exhibits 25 or 26 punctures from the pterygoid or palatine teeth, and, on each side, one or two, rarely three, circular wounds produced by the principal poison-fangs and by the reserve teeth. III. ViperidcE (Solenoglypha). — The sole indication of the bite consists of 8 or 10 punctures from the palatine or pterygoid teeth, and one little round wound, on each side, produced by the poison-fangs. (After Sir Joseph Fayrer.) Fig. 7, above, shows how it is possible to distinguish the marks left by a no7i-venomous reptile, and by one of the Proteroglypha or Solenoglypha respectively. Poison- glands. — The poison-glands occupy an extensive inter- muscular space behind the eyes, on each side of the upper jaw. GENEBAL CLASSIFICATION OF POISONOUS SNAKES 11 They are oval in shape, and may, in Naja tripudians for example, attain the size of a large almond (fig. 8). Their structure is the same as that of the salivary glands of the larger animals. The poison that they secrete accumulates in their acini and in the efferent duct that opens at the base of the corre- sponding fang. Each gland is surrounded by a capsule, to v^hich are partly attached the fibres of the masseter muscle, which violently com- presses it and drives the poison, just as the piston of a syringe would do, in- to the canalicule or groove of the fang. In a few venom- ous snakes the gland is developed to such an extent that it ex- tends as far as the first ribs. The species, on the contrary, that have the poison- teeth placed in the hinder part of the mouth (Opisthoglypha) have glands but little developed. Muscular Apparatus of the Head.— 'Figs. 9 and 10, 11 and 12 show the arrangement of the principal muscles that work the jaws and glandular organs in Vipera russellii and Naja tripudians, which respectively represent the most formidable types of Viperidai and venomous Cohcbridce. It is not necessary to give a detailed description of each of these muscles. Let it suffice to point out that all contribute in giving the greatest elasticity to the jaws, and at the same time strength Pig. 8. — Poison-gland and Pangs of a Venomous Snake (Naja tripudians, Colubriclce). (Natural size.) D, Lobe of the gland ; d, poison-duct ; f, fang attached to the maxillary bone ; G G, gland ; m, capsule of mucous membrane surrounding the fangs ; b, reserve fangs ; A A, muscular fascia covering the gland. (After Sir Joseph Payrer. ) 12 VENOMS A A, Fascia cover- ing the anterior and posterior temporal muscles ; b, small gland ; c, tendin- ous insertion of the fascia ; d, poison- duct ; E, poison- fang ; F, reserve fangs; G, mandible; H, ectopterygoid muscle ; j, poison-gland covered by the masseter ; k, masseter m the mandible ; l, insertion of the temporal muscle ; m, digastric muscle. inserted A A, Ectopterygoid muscle ; b, prse-spheno-pterygoid muscle ; c, intermandibular muscle ; d, prse- spheno-palatine muscle ; e, prse- spheno-vomerine muscle ; f, cap- sule of mucous membrane sur- rounding the fangs ; g, long muscle of the neck. Pigs. 9 and 10.— Muscdx-ab Appaeatus and Poison-gland of Vipera l ussellii (ViperidcB). (After Sir Joseph Fayrer. GENERAL CLASSIFICATION OF POISONOUS SNAKES IS A, Tracheo mastoid muscle; bb, digastric muscle ; c c, posterior temporal muscle; D D, anterior temporal muscle ; e e, massoter ; r, poisou-glaud, covered by the masseter and fascia ; G, poison-duct ; h, maxillary bone ; i, neuro-mandibular muscle ; j, costo- mandibular muscle. A, Entopterygoid muscle ; b, poison-gland ; c, poison-duct ; D, poison-fangs; E, prse-sphe- no-palatine muscle; p, prse- spheno-vomeriue muscle ; g, capsule of mucous membrane surrounding the fangs ; h, prse- sphenopterygoid muscle (which erects the fangs) ; J, inter-man- dibular muscle ; ic, ectoptery- goid muscle ; L, long muscle of the neck (longus colli). Figs. 11 and 12.— Muscular Appahatus and Poison-gland of Naja tripiidians (ColtLhridcc). (After Sir Joseph Fayrer.) 14 VENOMS sufficient to retain the prey and to cause it to- pass from front to rear towards the oesophagus, by a series of alternate antero-posterior movements and analogous lateral ones. By means of these move- ments, which are participated in by the upper and lower maxillary bones, the palatines, mandibles or inter-maxillaries, and the ptery- goids, the animal in a manner draws itself over its prey like a glove, since the arrangement of its dentition does not admit of juastication. Fig. 13. — Arbangement of the Scales of the Head in one op THE Non-poisonous ColitbrklcB (Ptyas mucosus). (After Sir Joseph Fayrer.) A, Rostral scale; b, anterior frontals; b', posterior frontals ; c, vertical; D, occipi- tals ; E, supra-ciliaries ; f, temporals ; l, m, nasals ; N, loreals, or freiials ; o, anterior oculars, or prse-orbitals ; p, posterior oculars, or post-orbitals ; q, supra-labials ; g, median infra-labial ; hh, lateral infra-labials ; i k, mentals. The enormous extensile power of the mouth and oesophagus thus enables snakes to swallow animals, the size of which is several times in excess of their own diameter. Deglutition is slow and painful, but the gastric and intestinal juices are so speedy in action, that the digestion of the most GENEBAL CLASSIFICATION OF POISONOUS SNAKES 15 resistant substances rapidly takes place. The very bones are dis- solved, and the faeces, which are voided some days later, contain only a few osseous remains and a felt-like material composed of hair or feathers. Scales.— The skin of snakes, which is very elastic and extensile, is covered with scales, small on the back, and in great transverse plates on the entire ventral surface. Pig. 14. — Abeangement of the Scales op the Head in one op the Poisonous Colubridcs {Naja tripudians, or Cobra-di-Capello). (After Sir Joseph Payrer.) The shape and dimensions of the scales of the head are highly characteristic in each species. It is therefore necessary to know their names and the arrangement that they exhibit : these details are shown with sufficient clearness in figs. 13 and 14. Coloration. — The colouring exhibited by the scales of snakes is governed generally by the biological laws of mimicry. It is therefore not a character of specific value, and may be modified several times in the course of the existence of the same reptile, according to the surroundings in which it is obliged to live. 16 VENOMS "Nature," write Dumeril and Bibron, "seems to have caused the tints and colours of snakes to vary in accordance with their habits and modes of life. Generally speaking, the colours are greyish or dull in species that are wont to live among sand, or which bury themselves in loose earth, as also in those that' lie in wait on the trunks or large boughs of trees; while these hues are of a bluish-green, resembling the tint of the leaves and young shoots of plants, in snakes that climb among bushes or balance themselves at the end of branches. It would be difficult to describe all the modifications revealed by a general study of the colours of their skins. Let us imagine all the effects of the decomposition of light, commencing with white and the purest black, and passing on to blue, yellow, and red ; associating and mixing them together, and toning them down so as to produce all shades, such as those of green, of violet, with dull or brilhant tints more or less pro- nounced, and of iridescent or metallic reflections modified by spots, streaks, and straight, oblique, undulating, or transverse lines. Such is the range of colours to be found in the skin of snakes." This skin is covered by a thick epidermis, which is periodically detached in its entirety, most frequently in a single piece. Before effecting its 77ioult, the reptile remains in a state of complete repose for several weeks, as if asleep, and does not eat. Its scales grow darker and its skin becomes wrinkled. Then one day its epidermis tears at the angle of the lips. The animal thereupon wakes up, rubs itself among stones or branches, divests itself entirely of its covering as though it were emerging from a sheath, and proceeds forthwith in quest of food. The 7nouU is repeated in this way three or four times every year. 17 CHAPTER II. HABITS OF POISONOUS SNAKES. THEIR CAPTUBE. All poisonous snakes are carnivorous. They feed on small mammals (rats, mice), birds, batrachians, other reptiles or fish, which they kill by poisoning them by means of their fangs. They almost always wait until their prey is dead before swallowing it. Some of them are very fond of eggs, which they well know how to find in the nests of birds, and swallov/ whole. When a poisonous snake wishes to seize its prey, or strike an enemy, it raises its head, and depresses the lower and elevates the upper jaw in such a way that the fangs are directed straight forward. Then, with the quickness of a spring when it is released, the reptile makes a sudden dart and strikes its victim. After inflicting the wound it draws back, doubles up its neck and head, and remains prepared to strike again. So rapid is the action of the venom, that the wounded animal falls to the ground almost immediately ; it is forthwith stricken with paralysis, and dies in a few moments. In most cases the snake holds it in its mouth until death ensues ; the reptile then sets to work to swallow its victim, an operation which is always slow and painful. In captivity poisonous snakes almost always refuse to take any food whatever. If it be desired to keep them for a long time, it is often necessary to resort to artificial feeding. For this purpose the snake is seized by the head by means of a strong pair of long forceps ; it is then grasped by the neck with the left Hand without 2 1» VENOMS Fig. 15. — Feeding a Poisonous Snake, Fiest Stage. HABITS OF POISONOUS SNAKES. THE IB CAPTUBE 19 squeezing too hard (fig. 15), talcing" care at the same time not to give the body a chance of coihng itself round anything. Next, one ov more lumps of beef or horse-flesh are introduced into the jaws, and gently forced down deep into the oesophagus by means Fig. 17.— Catching a Cobra-di-Cajpello (Naja iripudians), First Stage. (At the French Settlement of Pondicherry, in India.) of a glass rod, which is polished in order not to injure the mucous membrane. The oesophagus is then gently massaged in a down- ward direction, in order to cause the bolus Of food to descend into the stomach (fig. 16). This operation is repeated every fortnight. In this way, at my laboratory, I have been able to preserve, in perfect condition for more than two years, Indian Cobras and 20 VENOMS Fers-cle-lance from Martinique, taking care to keep them in a hot- house, at a temperature of about 82° to 86° F. It is also very important to place inside the cases a vessel full of water, which should be frequently changed, for almost all snakes drink often and like to bathe for whole days at a time. Fig. 18. — Catching a Cohra-di-Capello (Naja trlpndians). Second Stage. (At the French Settlement of Pondicherry, in India.) Within their reach should be placed in addition branches and rockwork, against which they rub at the moulting times, in order periodically to rid themselves of their scarf-skin. While moulting, snakes must neither be touched nor fed, since to force them to take food at such a time would be fatal. Snake-catching . — The captm'e of poisonous snakes, in order to keep them alive, can only be performed without danger by skilful persons, who are possessed of much coolness. HABITS OF POISONOUS SNAKES. THEIR CAPTURE 21 The best way of securing" them is suddenly to pin the neck to the ground by means of a stick held horizontally, or a small two- pronged fork of wood or metal (fig. 17). The stick is rolled along until close to the occiput (fig. 18). The animal can then be seized with the hand immediately behind the head, in such a way that it is impossible for it to turn and bite. It is then put into a wire cage, provided with a small mov- able trapdoor, with the fas- tening on the outside. In this way poisonous snakes can be sent to a distance, and left without food for one or even two months, provided that they be kept in a place which is somewhat moist and suffi- ciently warm. Fig. 19 shows how cap- tured cobras are carried in India, in the environs of Pondicherry. They are en- closed in earthern chatties, or in baskets of plaited bamboo, which are pro- vided with covers, and are very convenient for carrying snakes short distances. Pig. 19.— Hindu caerying Two Captured Cobras in "Chatties." 22 CHAPTER III. DESCBIPTION OF THE PRINCIPAL SPECIES OF POISONOUS SNAKES. THEIR GEOGRAPHICAL DISTRIBUTION. Poisonous snakes are especially common in the tropical zones of the Old and New Worlds. The species found in Europe are but of small size and not very formidable. In hot countries, on the other hand, they attain large dimensions, their venom is much more active, and, although they hardly ever attack man, and in most cases avoid hnn, they cause a considerable number of fatal accidents. It is sometimes a rather difficult matter to recognise from the mere appearance of a snake whether it is poisonous or not. Natu- rahsts themselves are occasionally deceived. It is therefore useful to learn to distinguish the most dangerous species by their external •characters, and to know in what countries there is a risk of their being encountered. A.— EUROPE. Of the continents of the Old World, the poorest in poisonous ■snakes is Earope. The only species found there are a Ccelopeltis (belonging to the Sub-family Dipsado7norpliin(B of the Opistlio- glypha), and certain Viperin^, which rarely exceed 75 centimetres in length. CoiLOPELTis, the cranial skeleton and head of which are repre- ^sented in fig. 20, is characterised by a narrow, concave frontal shield, THE PBINCIPAL SPECIES OF POISONOUS SNAKES 23 projecting supraciliaries, short snout, large eyes, with round pupils, two poison-fangs at the back of the upper maxillaries, and a cylindrical body. The scales of the back are finely grooved, and in the adult slightly concave. The coloration, olivaceous- brown, or deep red on the back, becomes on the ventral surface pale yellow with brown streaks, and from five to seven longitudinal series of small spots, which are blackish and edged with yellov^ on the sides. The mean total length is 1,800 milhmetres. The tail is somewhat tapering, and about 850 millimetres long. The only European species is Coelopeltis monspessidana, which is met with pretty com- monly in France, in the neighbourhood of Montpellier, and Nice, near Valencia in Spain, and in Dalmatia. It is likewise found throughout North Africa, and in Asia Minor. A second species, Coelopeltis moilensis, occurs in Southern -^m. 20.— Maxillaby, Mandible, and Tunis, Egypt, and Arabia. Head of Ccelopeltis monspcssulana. The European ViPBEiNiE belong exclusively to the Genus Vipeea, the principal zoological characters of which are as follows : — Head distinct from the neck, covered with small scales, with or without frontal and parietal shields ; eyes small, with vertically 24 VENOMS elongate pupils, separated from the labials by scales ; nostrils lateral. Body cylindrical. Scales keel-shaped, with an apical pit, in from 19—31 rows ; ventral scales rounded. Tail short ; sub- caudal scales in two rows. The Genus Vipera is represented in Europe by several species, which are likewise found in Western Asia and North Africa. These species are : — V. ursinii, V. berus, V. aspis, V. latastii, and V. ammodytes} Yipera ursinii. Snout obtuse, soft on its upper surface, with the frontal and parietal shields distinct, the former about one and a half times as long as broad, and almost always longer than the parietals. A single series of scales between the eyes and the free margin of the lips. Temporal shields smooth. Body scales in from 19 to 21 rows, strongly keeled on the back, less strongly on the sides. Colour yellowish or pale brown above, grey or dark brown on the sides, sometimes uniform brown ; spots more or less regular on the vertebral column, oval, elliptic or rhomboidal, dark brown or flecked with white, sometimes forming an undulous or zigzag band ; two or three longitudinal series of dark brown or black spots on the sides ; small dark dots running obliquely from the eye to the angle of the mouth ; nose and lips white, and one or two dark angular streaks on the head ; chin and throat yellowish ; belly black, with trans- verse series of white or grey dots. No sexual differences in coloration. Total length from 420—500 millimetres ; tail 50—55. ' As regards the distinctive characters of these various snakes, and of the majority of those that we shall describe in this book, we have followed tlie state- ments in the " Catalogue of the Snakes in the British Museum (Natural History)," vol. iii., by George Albert Boulenger, F.R.S. (London : Printed by order of the Trustees, 1896.) THE FlUNCIPAL SPECIES OF POISONOUS SNAKES 25 Habitat : South-east France (Basses-Alpes) ; Italy (Abruzzi) ; Isti-ia ; Mountains of Bosnia ; Plains of Lower Austria ; Hungary (environs of Buda-Pesth). Yipera berus {Common Vii)er, or Adder). Snout rounded, short and truncate ; pupil vertically elongate ; vertical diameter of the eyes equal to or greater than the distance separating them from the mouth ; frontal and parietal shields dis- Pig. 21.— (i) Vipcra herns; (2) ViiJcra aspis ;■ (3, 4) Vipera ammodytcs. (Natural size.) tinct, the former as long as broad, usually shorter than the space separating it from the rostral shield ; 6—13 scales round the eyes ; one or rarely two series of scales between the eyes and the lips ; nasal shield single, separated from the rostral by a naso-rostral shield ; temporal scales smooth. Body scales in 21 rows (excep- tionally 19 or 23), strongly keeled ; 132—150 ventral shields ; 38 — 36 subcaudals. Colour very variable, grey, yellowish, olive, brown, or red above. •26 VENOMS generally with an undulating or zigzag band along the vertebral column, and a series of lateral spots. A black spot shaped like a V, an X, or a circumflex accent, on the head. The tip of the tail is yellow or reddish. Some specimens are entirely black. Total length from 350 to 700 millimetres ; tail 75 to 90. Habitat: Northern Europe, and especially the mountains of Central Europe; irregularly distributed in Southern Europe; Northern Spain and Portugal, Northern Italy, Bosnia, Caucasus. This viper, which is very common in France, ranges as far as the Scandinavian Peninsula to about the 65th parallel of North Latitude. It is sometimes met with among the mountains at &a altitude of about 6,500 feet (2,000 metres). It is found on heaths, in grass-lands, vineyards, and forests. Certain parts of the sandy moors of North Germany are literally infested with it. It abounds in the Jura, Isere, Ardeche, Auvergne, Brittany, Vendee, and the Forest of Fontainebleau. It seeks its prey by night, and feeds on voles, small birds, frogs, lizards, and small fish. During the summer it shows a preference for moist places, often even remaining in the water, in which it swims with ease. Light and fire attract it. It does not climb trees, but is frequently found coiled up on boughs of dead wood scattered on the ground. When on the defensive, and preparing to bite, it throws its head back, and makes a sudden dart of from a foot to sixteen inches. If irritated it makes a sort of hissing noise. To pass the winter it retires into the crevices of rocks or into old tree-trunks, where it entwines itself closely with a number of its congeners. In this way ten or fifteen vipers are frequently found together in the same hole. In April, the whole company awakes, and copulation then takes place. The eggs are laid in August and September, and the young immediately crawl out of the shell, already prepared to bite, and THE PRINCIPAL SPECIES OF POISONOUS SNAKES 27 capable of finding their own food. Their length at birth amounts to 230 millimetres. The two glands of an adult adder contain about 10 centigrammes of poison. This small quantity is sometimes sufficient to cause death ; out of 610 persons bitten, Eollinger returns 59 deaths, or about 10 per cent. In the departments of Vendee and Loire-Inferieure alone, Viaud Grand Marais has noted during a period of six years 321 cases of bites from adders, 62 of which were followed by death. In Auvergne, Dr. Fredet^ (of Eoyat) returns 14 cases, which caused 6 deaths. Yipera aspis (Asj:), or Bed Viper). (Fig. 21, ,?, and fig. 22.) Snout shghtly turned up, soft and squarely truncate ; vertical diameter of the eyes equal to the space separating them from the mouth ; upper surface of the head usually covered with small, imbricate, smooth or feebly keeled scales, in 4 — 7 series, between the supraocular shields, which are prominent. The frontal and parietal shields are usually wanting ; sometimes they are distinct, but small and irregular ; the former are separated from the supra- oculars by two series of scales ; 8 — -13 scales round the eyes ; two (rarely three) series of scales between the eyes and the labials ; nasal shield single, separated from the rostral by a naso-rostral shield. Body scales in 21—23 rows, strongly keeled ; 134—158 ventrals ; 32 — 49 subcaudals. Coloration very variable, grey, yellowish, brown, or red above, with a zigzag band as in V. berus. Usually a black U-shaped mark on the hinder part of the head, with a longitudinal black streak behind the eyes ; upper lip white, or yellowish. Ventral surface yellow, white, grey, or black, with lighter or darker markings. Total length, 620—675 millimetres ; tail 75—95. ' Acad, dt; mcdccine, March 19, 1889. 28 VENOMS Habitat: France (especially Vendee, the Forest of Fontaine- bleau, and the South), Pyrenees, Alsace-Lorraine, the Black Forest, Switzerland, Italy and Sicily, and the Tyrol. This viper especially fre- quents dry, rocky, and arid hillsides, which are exposed to the sun. Like the adder, it hibernates in tree-trunks and old walls. It lays from 6 to 15 eggs, from which the living young immediately issue, provided with poison. It feeds upon small rodents, worms, insects, and young birds. Eaptorial birds, storks, and hedgehogs pursue FiG.2-2.—Vi2}eraas2ns. (Natural size.) devour it in large (From the Forest of Fontainebleau.) numbers. Yipera latastii. Intermediate between V. aspis and V. ammodijtes. Snout less turned up into a corneous appendage than in the latter. Head covered with small, smooth, or feebly keeled, subimbricate scales, among which an enlarged frontal shield may sometimes be dis- tinguished ; 5—7 longitudinal series of scales between the supra- ocular shields ; 9 — 13 scales round the eyes ; 2 or 3 series between the eyes and the labials ; nasal shield entire, separated from the rostral by a naso-rostral. Body scales in 21 rows, strongly keeled ; 125 — 147 ventrals ; 32—43 subcaudals. Coloration grey or brown above, with a longitudinal zigzag band, usually spotted with white ; head with or without spots on THE PRINCIPAL SPECIES OF POISONOUS SNAKES 29 the vertex ; black streak behind the eyes ; ventral surface grey, spotted with black and M'hite ; tip of the tail usually yellow or with yellow spots. Total length, 550—610 milHmetres ; tail 80—85. Habitat : Spain and Portugal. Yipera ammodytes. (Pig. 21, 3 and 4). Snout terminated in front by a horny appendage covered with 10 — 20 small scales ; vertical diameter of the eyes less than the distance separating them from the mouth ; upper surface of the head covered with small, smooth, or feebly keeled scales, among which .an enlarged frontal and a pair of parietal shields are some- times distinguishable; 5—7 longitudinal series of scales between the supraoculars ; 10—13 scales round the eyes ; two series between the eyes and the labials ; nasal shield entire, separated from the rostral by a naso-rostral. Body scales in '21-23 rows, strongly keeled ; 133—162 ventrals ; 24—38 subcaudals. Coloration grey, brown, or reddish above, with a zigzag dorsal band, usually spotted with white ; black streak behind the eyes ; belly grey or violaceous ; end of the tail yellow, orange, or coral-red. Total length, 550—640 millimetres ; tail 70—80. Habitat : Southern Tyrol, Carinthia, Styria, Hungary, Danubian principaHties and kingdoms, Turkey. Does not pass beyond the 48th parallel of North Latitude. This viper loves very sunny places, and hillsides planted with vines. It rarely hibernates. In districts in which it is plentiful, it is only necessary to light a fire at night in order to attract this species in swarms ; this is the best method of taking it. Its food consists of small rodents, lizards, and birds. 30 VENOMS B.-ASIA, DUTCH INDIES, AND PHILIPPINE ISLANDS. The species of snakes most dangerous to man are found in the warmer regions of Asia. India especially is infested by the famous Cobra-di-Capello {Naja tripitdians) , which possesses the highly remarkable faculty of dilating its neck in the form of a hood when n-ritated, and whose sculptured image appears on almost all the Hindu monuments. We shall describe in a separate section (see below, F.) the Hydrophiin^, or Secirsnakes, a large number of species of which frequent the shores of the Indian Ocean, the Strait of Malacca, the China Sea, the Moluccas, Celebes, and North Australia. In the case of cert^iin species the area of distribution includes the whole of the tropical and sub-tropical zones of the Pacific Ocean, as far as the West Coast of America. It is therefore preferable to group them together for the purpose of comprehensive study. Besides the above, the continent of Asia harbours a multitude of poisonous snakes belonging to the two Families Colubrid^ and VlPEEID^. The genera and species belonging to these are so diverse; that we must confine ourselves to mentioning the essential characters of those that present most interest. I. — Family Colubrid^. / (a) Bungariis. I (b) Naja. Subfamily Elapin^. : Genera J (c) Hemihungarus. (d) Callophis. (e) Doliopliis. ■ (a) Bungarus. Head hardly distinct from the neck ; eyes small, with round or vertically elliptic pupils ; nostril between two nasal shields. Two large poison-fangs followed by one or two small, slightly grooved 1 THE riUNCIl'AL Sl'ECIES OF POISONOUS SNAKES 81 teeth. (fig. 23). Scales smooth, obhque, m 13—17 rows, enlarged and hexagonal in shape on the vertebral column ; ventral scales round. Tail relatively short ; subcaudal scales in one or two rows. Two very dangerous snakes found in India and Indo-China belong to this genus, B. fasciatus and B. ccmdidus (var. cceruleus). Both are fairly common. In Ceylon B. cetjlonicus is met with, Fig. 23.— Skull of Bimgarus. (After G. A. Bouleager, o/j. cit.) . and in South China B. ccmdidus (var. muUicinctus) . The length of these snakes is from 1,000—1,500 millimetres. The back is compressed in the shape of a keel. The neck is not dilatable. 1. B. fasciatus {Banded Krait). Colour bright yellow, ringed with black, with a black band commencing between the eyes, and broadening behind upon the nape and neck (fig. 24). i J 32 VENOMS Especially abundant on the Coronmndel Coast, in Bengal, and in Burma. In the North-west Provinces of India it is known as the Kocha-Krait. Its bite is very serious, but does not cause nearly so many fatalities as that of the Cobra, since its fangs are smaller. Dogs bitten by B. fasciaiiis die in from four to five hours. Fig. 24. — Biincjariis fasciatus (India). (After Sir Joseph Payrer.) 2. B. candiclus. Blackish-brown or bluish, with narrow transverse white streaks, or small white spots, or alternate rings of yellow and dark brown ; belly 'white. Smaller than the foregoing, scarcely exceeding 1,000 millimetres in length. It is known as the " Krait " in India, where, THE PBINCIPAL SPECIES OF POISONOUS SNAKES 33 after the Cobra, the variety cceruleus causes most deaths among human beings. It is found in jungles and rice-fields, and commonly secretes itself in old trees and old walls. It frequently penetrates into houses, verandahs, bathrooms, and even beds. Sir Joseph Fayrer relates the story of a lady, who, when travelling in a palanquin, found on arriving at her destination a " Krait " coiled up in her luggage, the snake having thus made the journey with her throughout a whole night. The Krait may easily be confused with Lijcodon aulicus, a harmless snake which closely resembles it, though it can at once be distinguished by examining its mouth. (b) Naja. (Fig. 26.) Head scarcely distinct from the neck ; eyes with round pupils ; nostril between two nasal shields and an internasal. A pair of sohd grooved poison-fangs. Body elongate, cylindrical, terminated by a conical and pointed tail. Scales smooth, disposed obliquely, in 15 — 25 rows. Ventral scales round. N. tripudians (Gohra-di-Capello). (Fig. 26.) • Head small, covered with large shields, a frontal as long as broad, a supraocular, a prseocular, 3 postoculars, 2 -t- 3 or 8 + 3 temporals, 7 upper labials, 4 lower labials. Neck dilatable by the separation of the first cervical ribs ; 21 — 35 scales round the neck, 17—25 round the middle of the body : 163—205 ventrals ; 42—75 subcaudals. Total length, 1,500—1,900 millimetres ; tail 230. Coloration very variable, usually cinereous grey or almost black with a bluish sheen ; belly lighter, sometimes tinted with red. The head is frequently tinged with golden-yellow ; it is spotted with yellowish- white above, and is pure white underneath. 3 34 VENOMS This species is distributed throughout the whole of Southern Asia, from the south of the Caspian Sea to South China and the Malay Archipelago. Several varieties occur, and of these the principal are : — Fig. 25.— Skull op Naja tripiidiaas. (Afber G. A. Bouleager, op. cit.) (1) Var. Typica (fig. 27), with a black-and-white spectacle- shaped mark on the middle of the dorsal surface of the most dilatable portion of the neck, and one or more dark transverse bands on the ventral surface, behind the head. Habitat: India, Ceylon. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 35 (2) Var. Ccsca. — Colour, pale brown or uniform dark grey, without mark on the neck, and with one or more dark transverse bands on the anterior part of the belly. Habitat : Transcaspian region, India, Java. (3) Var. Fasciata. — Colour, brown, olive, or black, with more or less distinct light trans- verse bands. White spot edged with black in the shape of a ring or of a U on the neck, behind ; a black spot on each side in front. Habitat: India, Indo-China and South China, Hainan, Cam- bodia, Siam, Malay Peninsula. (4) Var. Sputatrix. — Black' or dark brown, with yellow or orange- coloured spots on the sides of the head and neck. The young have a pale spot in the Fig. 26. — Naja tripicdians {Cobra-di-Capello) on the shape of a U Or an 0 Defensive, pbeparing to Strike. on the middle of the dorsal surface of the neck, and the throat is whitish. Habitat : Chusan Islands and South China, Burma, Malay Peninsula, Sumatra, Java. (•5) Var. Leucodira. — Brown or black, without mark on the neck. Throat yellowish-white, followed by a black transverse band. Habitat : Sumatra, Malay Peninsula. • 36 VENOMS (6) Var. Miolepis. — Brown or black ; sides of the head and throat yellowish, no mark on the neck. Young with white rings completely encircling the body and tail. i Habitat : Sarawak, Labuan, Borneo. Fig. 21.— Kcija In'x^vdians (Cobra-di-Capello). (After Sir Joseph Fayrer.) Naja samarensis. Internasal shields shorter than the prsefrontals, and in contact with the prceoculars; 1—3 large occipital shields behind the THE PBINGIFAL SPECIES OF POISONOUS SNAKES 37 parietals ; ] prseocular and 3 postoculars ; '2 + 2 ov 2 + 3 tem- porals ; 7 supralabials, 4 infralabials ; 21 — 28 scales across the neck, 17—19 across the middle of the body; 159—175 ventrals ; 45 — 50 subcaudals. Coloration black or sometimes yellowish above; pale brown or yellowish on the belly ; neck black. Total length, 1,000 millimetres ; tail 160. Habitat: Philippine Islands. Naja buiigarus {OpMophagus or Hamadryas elaps). (King Cobra or Hamadryad.) A pair of large occipital shields ; 1 praeocular ; 3 postoculars ; 2 + 2 temporals ; 7 supralabials, 4 infralabials ; 19 — 21 scales across the neck, 15 across the middle of the body ; 215 — 262 ventral scales, 80 — 117 subcaudals. Neck dilatable. Coloration very variable, yellowish, brown, olive, or black, with or without dark transverse bands. Total length, 3,900 millimetres ; tail 630. Habitat : India, Burma, Indo-China, Siam, Southern China, Malay Peninsula ami Archipelago. The species of Naja are oviparous, and usually lay some twenty eggs, elliptical in shape and as large as those of a pigeon, with a soft shell. These snakes do not fear the proximity of man, and feed upon rats, mice, and birds ; they seek their prey chiefly in the evening, after sunset. They swim extremely well, and frequent the neighbourhood of water-courses. Indian legends relate that Brahma, having descended on earth and fallen asleep one day at high noon, a Naja placed itself in front of him and, dilating its broad neck, procured for him kindly shade. In order to repay it for the service rendered, Brahma gave 38 VENOMS Naja the marks that it bears on its neck, intended to frighten the kites and other birds of prey, which are implacable enemies of this snake. When a native of the Malabar Coast finds a Naja in his dwelling, he begs it in a friendly way to depart ; if the request be without avail, he offers it food in order to attract it outside ; if the snake still does not move, the Hindu goes in search of the pious servitors of one of his divinities, who, procuring an offering, address the most touching supplications to it (Brehvi). The mortality due to the bite of this snake, which is by far the most common in India, is considerable. In the course of a period of eight years, from 1880 to 1887, it amounted on the average to 19,880 human beings and 2,100 head of cattle every year. In 1889, 22,480 persons and 3,793 head of cattle perished from snake-bite. Since then, the annual tale of fatalities always fluctuates between 16,000 and 22,000, in spite of the rewards for the destruction of snakes which the Indian Government has been obliged to institute, which represent an expenditure of about £10,000 per annum. For every 100 persons bitten, it is estimated that on an average from 25 to 80 die, and in most cases death supervenes in from two to twelve hours after the bite. Naja hungarus, or the Hamadryad, is the largest and most formidable of poisonous snakes. It is very vigorous and very aggressive, but is more rarely met with than Naja tripudians. It loves the vicinity of rivers and streams, lives in forests and jungles, and climbs trees with facihty. It feeds upon other snakes (whence its name Ophiophagus), and also on birds, fish, and small mammals. Hindu snake-charmers assert that it is very difficult to capture, and dangerous owing to its strength ; they handle it only after having extracted its poison-fangs. A very intelligent Hindu told Torrens how he had seen the w&y in which the Hamadryad procures the snakes that form its favourite THE PRINCIPAL SPECIES OF POISONOUS SNAKES 39 food. The Hindu in question happened to be on the flat roof of his house, when a young Hamadryad appeared quite close to him. The snake raised its head, expanded its neck, and emitted a shrill hissing noise. Thereupon a dozen snakes came crawling up from all directions and assembled round the Hamadryad, when the latter made a dart at one of them and hastened to devour it {Fayrer). The Hamadryad is dreaded with good reason, for not only is it aggressive, and hurls itself boldly upon its adversary, but it also pursues him, a trait exhibited by no other poisonous snake. Cantor relates that in Assam an officer met with several young Hamadryads which were being watched over by their mother. The latter turned towards its enemy, who took to his heels with all speed, pursued by the terrible reptile. The course taken led to a river, which the fugitive did not hesitate to swim in order to gain the opposite bank, hoping thus to make good his escape; all, however, to no purpose. The snake still pursued him, and the officer saved himself only by a stratagem. He dashed his turban on the ground ; the snake threw itself upon it and savagely bit it several times, thus giving the officer time to reach a place of safety. Cantor's experiments show that the venom of the Hamadryad is extremely rapid in its action. A dog usually dies a quarter of an hour after being bitten, and Nicholson states that he has seen an elephant bitten by a snake of this species die in three hours. (c) Hemibungarus. This genus includes several species of snakes of somewhat small size, rarely exceeding 700 milhmetres in length, with an elongate, cylindrical body ; the head is scarcely distinct from the neck, the pupil round, and the tail short, while the nostril is situate between two nasal shields. The temporal shields are arranged in a single row. The poison-glands sometimes extend into the abdommal 40 VENOMS cavity. Scales m 13 or 15 rows ; 190-260 ventrals, 12-44 sub- caudals in 2 rows. Four species beloDging to this genus are known :— (1) H. caUigastei:~2 + 3 temporal scales, 6 supralabials. Colour purple, with black transverse bands separated by narrow white bars ; belly and end of tail red ; snout yellow, with a black band on the upper lip below the eyes. Total length, 520 millimetres ; tail 30. Habitat : Philippine Islands. (2) H. coUaris. — No anterior temporal scales. Colour black on the back, with black and red bands on the belly ; a yellow collar on the occiput. Total length, 430 millimetres ; tail 15. Habitat : Philippine Islands. (3) H. nigresceyis.— Scales in 13 rows. A single temporal scale ; 218—251 ventrals ; 33—44 subcaudals. Belly uniformly red ; upper lip yellow in front of and behind the eyes. Total length, 1,100 milhmetres ; tail 115. Habitat : Hills of Western India, from Bombay to Travancore. (4) H.japonicus.— Scabies in IS lows; 190— 216 ventrals ; 28—29 subcaudals ; temporals 1 + 1. Colour red on the back, with 1—5 black bands crossed by other black bands edged with yellow. Snout and sides of head black. Belly yellow, with large black spots alternating with black trans- verse bands. Total length, 520 millimetres ; tail 40. Habitat : Loo Choo Islands. (d) Callophis. This genus is characterised by the maxillary bones extending forwards beyond the palatines, with a pair of large poison-fangs, but without other teeth. Head and eyes small, pupils round; THE PRINCIPAL SPECIES OF POISONOUS SNAKES 41 nostril between two nasal shields. Body cylindrical, greatly elongate. Scales smooth, in 13 rows ; ventrals rounded ; sub- caudals in 2 rows. Five species are known : — (1) G. gracilis. — Eed or pale brown, with three longitudinal black lines passing through brown, or black spots ; the lateral spots alternating with the vertebrfe. Black and yellow bands under the tail and on the belly. Total length, 740 millimetres ; tail 35. Habitat : Malay Peninsula, Sumatra. (2) G. trimaculatus. — Head and nape black, with a yellow spot on each side of the occiput ; belly uniform red ; tail with two black rings. Total length, 335 millimetres ; tail 21. Habitat : India and Burma. (3) G. maculiceps. — Head and nape black, with one or two yellow bands on each side. Belly red, two black rings on the tail. Diameter of the eyes equal to two-thirds of the space separating them from the mouth. Total length, 485 millimetres ; tail 30. Habitat : Burma, Indo- China, Malay Peninsula. (4) C. macclellandii. — Head and neck black, with a yellow transverse band behind the eyes. The space separating the eyes equal to that separating them from the mouth. Colour reddish- brown on the back, with regular and equi-distant black streaks ; belly yellow, with black bands or quadrangular spots. The head exhibits two black transverse bands separated by a yellow band. Total length, 620 millimetres ; tail 55. Habitat : Nepal, Sikkim, Assam, Burma, Southern China. (5) G. bibronii. — Met with by Beddome in the forests of Malabar, at an altitude of 3,280 feet. Back purplish-brown, with a pearly lustre, and about forty irregular black transverse bands, extending to the tip of the tail. Head black in front, cherry-red on the occiput.. 42 VENOMS Total length, 640 millimetres; tail 50. Habitat : Malabar. All the snakes belonging to the genus Callophis are remarkable for their bright and varied colours, whence the generic name, which signifies " beautiful snakes." They feed exclusively on other snakes belonging to the Family GalamaridcB ; consequently they are not found in regions where Galamandce do not occur, as, for instance, in Ceylon. They are essentially terrestrial, and live in old tree-trunks, or clefts in rocks. They are sluggish, slow-moving, and chiefly nocturnal. As a rule they do not seek either to defend themselves or to bite; consequently fatal accidents caused by them are scarcely known in the case of human beings. Their venom, however, is very toxic to animals. (e) Doliophis. This genus exhibits the same characters as Callophis, except that the poison-glands, instead of being confined to the temporal region, extend a very long way on each side of the body, to about one-third of its length, gradually growing thicker and terminating at the base of the heart. It includes four species : — (1) D. bivirgatus. — Colour reddish-purple or black on the back, red on the head, tail, and belly. Total length, 1,610 millimetres ; tail 190. Habitat : Burma, Indo-China, Malay Peninsula, Sumatra, Java, and Borneo. (2) D. intestinalis. — Brown or black on the back, with darker or lighter longitudinal streaks ; tail red beneath ; belly red, crossed with black streaks. Total length, 580 millimetres ; tail 45. THE PUINCIPAL SPECIES OF POISONOUS SNAKES 43 Habitat: Burma, Malay Peninsula, Sumatra, Java, Borneo, Celebes. (3) D. hilineatus. — Black on the back, with two white streaks along the whole length of the body. Snout white ; belly striped with black and white bands. Tail orange, with two or three black rings or spots. Total length, 710 millimetres ; tail 45. Habitat: Philippine Islands. (4) jD. pJiilippinus. — Back with dark brown cross-bands, merging into black transverse ventral streaks, which are separated by yellow or red interspaces. Head brown, with small yellow spots. Total length, 430 mihimetres ; tail 35. Habitat : Philippine Islands. II. — Family Vipbrid^. The Family Vipeeid^ is represented in Asia by a considerable number of snakes belonging to the two Subfamilies 'ViPEEiNiE and Crotalin^. The Asiatic ViPERiNiE belong to the genera : — (a) Vipera. (b) Pseudocerastes. (c) Cerastes. (d) Echis. The CROTALiNiE consist of only two genera : — (e) Ancistrodon. (f) Lachesis. 1.— VIPERINiE. (a) Yipera. We shall not recapitulate here the characters of the Genus Vipera, which we described in dealing with the vipers of Europe. The genus is represented by several species, the geographical range of which is chiefly confined to Eastern and Central Asia. 44 VENOMS (1) Vipera renardi.—B.esemUes V. berus, but the snout is pointed and soft, with a turned-up tip; a single series of scales between the eyes and the lips ; nostril pierced in the lower half of a single nasal shield ; 8—9 supralabial shields ; 4 infralabials. Body scales in 21 rows ; 130—150 ventrals ; 24—37 subcaudals. Coloration the same as in the European V. ursinii, but the snout and lips are spotted with black or brown. Total length, 395—620 millimetres ; tail 40—75. Habitat : Central Asia, Turkestan. (2) V. raddii. — Snout rounded; supraocular shields erectile; eyes surrounded by a complete circle of 14 — 17 scales ; 9—10 supralabials ; body scales in 23 rows ; 150—180 ventrals ; 23 — 32 subcaudals. Coloration pale brown or grey on the back, with a dorsal series of small reddish spots arranged in alternating pairs. A black mark like a circumflex accent on the occiput, and a black band behind the eyes. Belly yellow, speckled with black and white. Total length, 740 millimetres ; tail 50. Habitat: Armenia. (3) V. lebetina.— Snout rounded and obtuse, with a well-marked prominence ; 7 — 12 longitudinal series of scales between the eyes ; supraocular shields well developed or narrow, or broken up into several small portions ; 12 — 18 scales round the eyes ; 9 — 12 supra- labials ; 4 — 5 infralabials; body scales in 23 — 27 rows; 147 — 180 ventrals ; 29 — 51 subcaudals. Coloration variable, grey or pale brown on the back, with a series of large dark spots. Large brown mark like a circumflex accent on the crown of the head and another on the occiput. Belly whitish, speckled with grey-brown ; end of tail yellow. Total length, 960 millimetres ; tail 120. The female may attain the length of 1,350 millimetres. Habitat : Cyprus, Galilee, Syria, Asia Minor, Transcaspia, Persia, Mesopotamia, Afghanistan, Baluchistan, Cashmir. THE PRINCIPAL SPECIES OF POISONOUS SNAKES 45 (4) V. russeUii (Daboia, or Eussell's Viper). (Fig. 28.) — This iper, which may attain a length of as much as 2,000 millimetres, ; magnificently coloured. Its dorsal surface is brownish-yellow, Fig. 28.— Vipera russellii (Syn. Vipera elegans. Daboia, or Russell's Viper). India. (After Sir Joseph Fayrer.) marked with large oval spots of blackish-brown, edged with yellow or white. The belly is covered with transverse bands, with beautiful triangular black spots, bordered with white. The head, which is long, ends in front in a thick, rounded snout ; it is covered above 46 VENOMS With small keeled scales. The nostril, which is large and laterally placed, is surrounded by three shields and soft smooth skin. The species is found throughout India, from Bombay to Bengal, in Ceylon, Burma, and Siam. It is particularly common in Burma, around Kangoon. For walking in the jungle and rice-fields, the natives of this region encase their feet and legs in a special kind of jack-boots made of coarse jute-cloth, in order to protect themselves from the bites of this snake, which cause a large number of fatal accidents. The Daboia ascends the Himalayas to an altitude of 5,250 feet. It lives in thickets, under stones, and in the clefts of rocks. When disturbed it makes a terrible hissing, but bites only when attacked or irritated. It feeds upon small vertebrates, such as mice, rats, birds, and frogs, and often enters "houses in pursuit of rats. " Schrott had the opportunity of observing a Daboia on the defensive. A lady carrying a child on her arm was returning home towards evening ; she had almost reached her house when a bull- dog accompanying her began to bark furiously. Although the lady saw nothing, she was, nevertheless, frightened and called for help. Schrott, who was not far away, ran to the spot, and saw a Daboia lying across the path by which the lady had to proceed. The reptile had its neck thrown back and its head in a horizontal position ; its bright eyes followed all the movements of the dog, to whose barks it replied by shrill hisses. It was only waiting for an opportunity to strike. Schrott called off the dog, and the snake at once disappeared among the high grass close by. Next day it was killed at the same spot" {Brehm). The venom of this viper is terribly potent. According to Eussell, a large dog exhibited symptoms of poisoning five minutes after being bitten. At the end of a quarter of an hour it lay down, uttering heartrending cries, began to breathe with difficulty and noisily, was seized with spasms of the jaws and cramps, and died in frightful agony less than half an hour after the wound was inflicted. Fowls THE PRINCIPAL SPECIES OF POISONOUS SNAKES 47 in most cases die iu less than two minutes. A horse succumbed in half an hour, and another in eleven hours. It appears that in India many cattle are killed by Daboias while grazing (Fayrer). (b) Pseudocerastes. (Pig. 29.) This genus is represented by a single species {Pseudocerastes persicus), which appears to be exclusively confined to Persia. The head is very distinct from the neck, and covered with small imbricate scales ; the eyes, which are small, have vertical pupils ; they are separated from the lips by small scales. The nostrils are directed upwards and outwards. The snout is very short and rounded. The cylindrical body has 23 — 25 rows of scales ; 151 — 156 ventrals 43 — 49 subcaudals. The coloration is gray or brown, with four series of large black spots, and the head exhibits two longitu- dinal black streaks behind the eyes, with black. Total length, 890 miUimetres ; tail 110. Fig. 29. — Pseudocerastes persicus. (After Dum^ril and Bibron.) The bellv is whitish, dotted (c) Cerastes. The vipers belonging to this genus are much more common in North Africa, and we shall therefore study them in conjunction with the African snakes. Cerastes cornutus alone, the special habitat of which is Egypt, is sometimes met with in Arabia and on the eastern bank of the Suez Canal. 48 VENOMS (d) Echis. Echis cwrinatus (the Phoorsa). (Fig. 30).— This viper is charac- terised by the subcaudal shields being arranged in a single row. It is savage and very aggressive, being always ready to attack. Its length does not exceed 600 millimetres at the most. The colour of the body is grey, more or less dark and adorned with streaks, spots, and dots of blackish-brown. The back displays yellowish- FiG. 30. — Echis carinatus. India. (After Sir Joseph Fayrer.) white wavy lines, forming X-shaped markings. The upper side of the head exhibits a yellow spot surrounded by brown, and other small black spots, the whole arrangement forming a fairly good representation of a cross. This species is found in India, Persia, Baluchistan, Arabia, and Palestine ; while, as we shall see, it also occurs in Africa. It is fairly common in the environs of Aden. THE PRINCIPAL SPECIES OF POISONOUS SNAKES 49 In moving over the ground a peculiar sound is produced by the friction of its scales. It is capable of springing with great agility a fairly long distance on to its prey. When it believes itself in danger it coils up, doubling its body twice in the shape of a crescent, in the middle of vs^hich it places its head, ready to strike. Its venom is very rapid in taking effect. 2.— CBOTALIN^. (e) Ancistrodon. The snakes belonging to this genus of CrotalincB are found in Central and Eastern Asia, but three important species occur in the New World, in the United States and Central America. The head is covered with nine large symmetrical shields, but the internasals and prfBfrontals are sometimes broken up into scales. The body is cylindrical; the tail rather short; the subcaudal scales are arranged in one or two rows. A. acutus. — The snout of this snake is prolonged into an append- age directed forwards. The head-shields are finely granulate. Body scales arranged in 21 rows ; 162 — 166 ventrals ; 58 — 60 subcaudals. Coloration brown on the back, with blackish -brown X-shaped spots ; head dark brown, yellow on the cheeks, with a black band running from the eye to the angle of the jaw ; belly yellowish, spotted with brown, with a series of large black transverse blotches. Total length, 1,600 millimetres ; tail 200. Habitat : Upper Yang-tse, China. A. halys. — Snout prolonged into an upturned appendage, blunt at the tip ; 7 — 8 supralabial scales, the third of which forms part of the margin of the eye ; body scales in 23 rows ; 149 — 174 ventrals ; 81 — 44 subcaudals. Coloration yellowish, grey, red, or pale brown above, with darker spots or cross-bars. A black spot on the snout ; two black spots 4 0 VENOMS Fig. 31.— Ancislrodoii hypnale. (The Caraiualla of Ceylon.) (After Sir Joseph Fayrer.) on the vertex ; a dark, light-edged band on the temple ; belly whitish, more or less speckled with grey or brown. Total length, 490 millimetres ; tail 65. Habitat : From the borders of the Caspian Sea and the Ural Eiver to the Upper Yenisei ; Turkestan. A. intermedins. — Kesembles the fore- going very closely, but the snout is not turned up at the end. Total length, 750 millimetres ; tail 85. Habitat : Central Asia, Eastern Siberia, Mongolia, and Japan. A. blo7nhoffii. — Similar to A. halys, but the snout is not turned up at the end, and the body scales are in 21 rows; 137 — 166 ventral scales ; 29 — 55 sub- caudals. Coloration very variable ; grey, brown, or red above, with large black-edged spots arranged in pairs ; black, light-edged band on the temple ; upper lip uniformly yellow or red ; belly yellow or reddish, more or less spotted with black, or almost entirely black. Total length, 720 millimetres ; tail 100. Habitat : Eastern Siberia, Mongolia, China, Japan, Siam. A. himalayanus. — Snout scarcely turned up, with a hard tip ; 5 — 7 supra- labial shields. Body scales in 21 (rarely 23) rows ; 144 — 166 ventrals ; sub- caudals in 35 — 51 pairs. THE PRINCIPAL SPECIES OF POISONOUS SNAKES 51 Coloration brown, with black spots or transverse bands ; black, light-edged band from the eye to the angle of the mouth ; belly- dark brown, or more or less whitish. Total length, 590 millimetres ; tail 90. Habitat: Himalayas (5,000 to 10,000 feet), especially in the North-west; Khasi Hills. This snake feeds chiefly on mice. A. rhodostoma. — Snout pointed, somewhat turned up at the tip : 7 — 9 supralabial shields ; body scales in 21 rows ; 138 — 157 ventrals ; 34 — 54 subcaudal pairs. Coloration reddish, grey, or pale brown above, with large angular, dark brown, black-edged spots arranged in pairs or alter- nating. Vertebral line almost black ; lips yellow, speckled with brown ; brown, black-edged band, running from the eye to the angle of the mouth. Belly yellowish, spotted with greyish -brown. Total length, 810 millimetres ; tail 90. Habitat : Java. A. hijpnale (fig. 31).— Snout more or less turned up, with a hard, pointed end ; 7—8 supralabial shields ; body scales in 17 rows ; 126 — 155 ventrals ; 28 — 45 subcaudal pairs. Coloration very variable ; brown, yellowish, or greyish above, sometimes with dark brown spots or transverse bands. Cheeks brown, with a longitudinal, white, black-edged streak on each side of the neck. Belly more or less speckled with dark brown. Total length, 480 mihimetres ; tail 65. Habitat: Ceylon, and Western Ghats of India as far north as Bombay. In Ceylon this snake is known as the Caraioalla. It is much dreaded, but its bite is not rapidly fatal. (f) Lachesis. This genus has many representatives in Asia and the New World. The American species are for the most part of larger size and more formidable. 52 VENOMS They are characterised by a triangular head, covered with small scales or small shields, and by a cyhndrical or compressed body. The Asiatic species have the subcaudal scales in two rows and the tail short, and often prehensile, which enables them to climb trees or bushes, where they lie in wait for their prey. Their classification is based upon the following characters : — A. First infralabial scale in contact with its fellow. I. Scales in 21—25 (rarely 27) rows ; 129—158 ventrals ; 21— 57 subcaudals ; 5 — 9 series of scales between the supraocular shields; tail non -prehensile. Fig. 32. — Lachesis okinavensis. (After G. A. Boulenger, oi). cit.) (1) L. monticola. — Supraocular shields large, separated by 5 — 8 scales ; snout obtuse. Colour brown or yellowish above, brown or pale yellow on the sides, with a brown temporal streak. Belly white, spotted with brown. Total length, 740 mihimetres ; tail 115. Habitat : Tibet, Himalayas (2,000 to 8,000 feet), Hills of Assam, Burma, Malay Peninsula, Singapore, Sumatra. (2) L. okinavensis (fig. 32). — Supraocular shields large, separ- THE PBINCIPAL SPECIES OF POISONOUS SNAKES 53 ated by a transverse series of G — 9 scales ; end of snout pointed and turned up. Colour brown above, with dark transverse bands and a light temporal streak. Belly brown, spotted with black, especially on the sides. Total length, 350 millimetres ; tail 60. Habitat : Okinawa, Loo Choo Islands. (3) L. strigatus. — Supraocular shields small, sometimes broken up, separated by 8 — 11 convex scales in juxtaposition. Colour brown above, with black spots often forming a median zigzag band ; temporal band black ; belly whitish, spotted with grey or black ; end of tail yellow or reddish. Total length, 480 millimetres ; tail 55. Habitat : Hills near Bombay, Deccan, Anamallays and Nil- gherries. II. Scales in 27—37 rows ; 174—231 ventrals ; 54—90 sub- caudals ; tail non-prehensile. (4) L. flavoviriclis. — Scales in 33—37 rows; 222 — 231 ventrals; 75 — 90 subcaudals ; 8—9 supralabials. Coloration pale brown or greenish-yellow above, marbled with black ; longitudinal black streaks symmetrically disposed on the head ; belly yellow or greenish, with darker spots. Total length, 1,215 milHmetres ; tail 220. Habitat : Loo Choo Islands. This snake is not infrequently termed by naturalists Trimeres- urus riuhianus. (5) L. cantoris. — Scales in 27 — 31 rows; 174 — 184 ventrals ; 55 — 76 subcaudals ; 13 supralabials. Coloration pale brown or dull green, with small black spots ; a whitish streak along the sides of the body ; belly white or greenish. Total length, 1,020 millimetres ; tail 140. • Habitat : Andaman and Nicobar Islands. 54 VENOMS III. Scales in 21—27 rows; 160—218 ventrals; 54—92 sub caudals ; tail not or scarcely prehensile. (6) L. jerdonii.—7—9 scales in a line between the supraocular shields; scales in 21 or 23 rows; 164—188 ventrals; 54—67 subcaudals. Coloration greenish-yellow or olive above, mixed with black, a dorsal series of reddish-brown transverse rhomboidal spots ; upper lip yellow, with one or two black spots ; belly yellow, more or less marbled with black. Total length, 930 millimetres ; tail 145. Habitat : Assam, Tibet, Upper Yang-tse. (7) L. mucrosquamatus.—lQ—15 scales in a line between the supraocular shields ; scales in 25 — 27 rows ; 183—218 ventrals ; 72 — 92 subcaudals. Colour brownish-grey above, with a series of large black median spots and smaller ones on the sides ; a black streak from the eye to the angle of the mouth; belly brownish, spotted with white. Total length, 1,050 millimetres ; tail 210. Habitat: Formosa, Assam. (8) L. luteus. — 12 or 13 scales in a line between the supraocular shields ; scales in 23 — 25 rows ; 182 — 186 ventrals ; 72—74 sub- caudals ; supraocular shields large. Colour yellow above, with a series of dark rhomboidal spots, and a dorsal, black-spotted zigzag band ; a black streak on each side of the head behind the eyes ; belly yellowish, spotted with gvej. Total length, 945 millimetres ; tail 164. Habitat : Loo Choo Islands. (9) L. purpureomaculatus. — 12 — 15 scales in a line between the supraocular shields ; scales in 25 — 27 rows ; ventrals 160 — 182 ; subcaudals 55 — 76 ; supraocular shield very narrow, sometimes broken up. Coloration purplish-black above, sometimes variegated with pale green ; flanks pale green ; belly olive or greenish-white, uniform or spotted with black. Some specimens are entirely green. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 55 Total length, 980 millimetres ; tail 150. Habitat: Himalayas, Bengal, Assam, Burma, Malay Peninsula, Andaman and Nicobar Islands, Pulo-Pinang, Sumatra. IV. Scales in 21 rows (rarely 19 or 23) ; 7 — 13 series of scales between the supraoculars ; tail i7iore or less prehensile. (10) L. gramineus (Syn. Tri- vieresurus gramineus. The Green Pit Viper).— 145 — 175 ventral scales ; 53 — 75 subcaudals ; snout slightly projecting ; supraocular shield narrow. Colour bright green, rarely olive or yellowish, with or with- out darker transverse bands ; end of tail yellow or red ; belly green, yellow, or white. Total length, 870 millimetres ; tail 150. Habitat : South-eastern Asia, Darjeeling, Himalayas, Ganges Delta, Siam, Southern China, Hong Kong, Formosa, Java, Sumatra, Timor. (11) L. flavomaculatus (fig. pig. SS.—Lachesis fiavomacidatus. 33). — 170 — 187 ventral scales ; (After G. A. Boulenger, op. cit.) 53 — 73 subcaudals ; snout pro- jecting, obliquely truncate; supraocular shield narrow. Colour bright green or olive, sometimes barred with reddish- brown ; belly green, olive, or greenish-yellow ; end of tail sometimes red. Total length, 1,060 millimetres; tail IGO. Habitat : Philippine Islands. VENOMS (12) L. su77iatranus.— 180— Vdl ventral scales; 58—82 sub- caudals; supraocular shield large. Coloration bright green, with or without black transverse bands; yellowish band on each side; belly yellow or green, with or without black speckles ; end of tail red. Total length, 1,100 millimetres ; tail 180. Habitat : Singapore, Sumatra, Borneo, Palawan. (13) L. a7mviallensis.—lS8—158 ventral scales; 44—58 sub- caudals. Colour green, olive, yellowish, or reddish-brown; a black temporal band; belly pale green, olive, or yellow; tail usually black and yellow. Total length, 730 milHmetres; tail 110. Habitat : Anamallay and Nilgherry Hills, South India. (14) L. trigonocephalus. — Scales in 17 — 19 rows, 145 170 ventrals ; 53—67 subcaudals. Coloration green, with or without black transverse bands or spots ; a black temporal streak ; belly green or yellow ; end of tail usually black. Total length, 790 millimetres ; tail 130. Habitat: Ceylon. (15) L. 7nacrolepis.— 8csi\es in 13 — 15 rows ; 134 — 143 ventrals ; 48 — 56 subcaudals. Colour bright green or olive ; belly pale green. Total length, 680 millimetres ; tail 120. Habitat : Southern India. B. First lower labial shield divided ; the portion separated off forms a pair of small supplementary dental shields; 144 — 176 ventral scales ; 38 — 57 subcaudals ; tdA\ prehensile. (16) L. pimiceus. — Scales in 21 — 23 rows ; 12 — 14 series of scales between the supraocular shields. Colour grey, brown, or red ; belly spotted with brown ; end of tail red. Total length, 640 millimetres ; tail 90. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 57 Habitat : Sumatra, Java, Borneo, Natuna Islands. (17) L. horneensis. — Scales in 19 — 21 rows ; 10 — 11 series of scales between the supraocular shields ; 152 — 168 ventrals ; 43 — 65 subcaudals. Total length, 770 millimetres ; tail 105. Habitat : Borneo, Sumatra. C. (18) L. toagleri. — Scales in 19 — 27 rows, 127 — 154 ventrals ; 45 — 55 subcaudals ; tail prehensile. Colour green, with darker or lighter markings, black and yellow, or nearly entirely black. .Total length, 980 millimetres ; tail 150. Habitat: Malay Peninsula and Archipelago. C— AFRICA. In Africa, poisonous snakes abound throughout the whole of the tropical and sub-tropical zones. The fatal accidents to human beings caused by them in this continent, are fewer than in India, since the population of Africa is less dense, but several species occur, the venom of which is especially dangerous to life. These species belong in nearly equal numbers to the Families CoLUBRiD^ and Vipebid^. I. — COLUBRID^. The poisonous CoLUBKiDiE of Africa are all included in the Subfamily Elapince, of which the following are the eight principal genera : — (a) Boulengerina. (b) Elapechis. (c) Naja. (d) Sepedon. (e) Aspidelaps. (f) Walterinnesia. (g) Homorelaps. (h) Dendraspis. 58 VENOMS (a) Boulengerina. A small snake '240 millimetres in length, the principal characters of which are as follows : — Maxillary bones equal to the palatines in length, with a pair of relatively large poison-fangs, followed by three or four small teeth. Head hardly distinct from the neck. Eye small, with round pupil ; nostril between two nasal shields. Body cylindrical ; scales smooth, in 21 rows ; ventrals rounded. Tail moderate ; subcaudal scales in 2 rows. The only knowii species, B. stormsi, is brown, with black transverse bars on the neck; tail black; belly white in front, brown behind, with a black border to the scales. It is found m the region of Lake Tanganyika. (b) Elapechis. This genus is characterised by the size of the maxillary bones, which is equal to that of the palatines ; a pair of large poison-fangs followed by two to four small teeth ; head not distinct from the neck ; eye small with round pupil ; nostril between two nasal shields. Body cylindrical; scales oblique, smooth, in J 3 or 15 rows; ventrals rounded. Tail very short, subcaudal shields in 2 rows. Six species are known : — (1) E. guentheri. — Scales in 13 rows. Snout short, rounded ; first lower labial shield in contact with its neighbour behind the symphysis. Internasal shorter than the prsefrontals ; length of frontal three-fourths of that of the parietals. Coloration whitish or grey above, with black, white-edged cross- bands. Belly dirty white, brownish, or grey. Total length, 520 millimetres ; tail 50. Habitat : Gaboon, Congo, Angola, Central Africa, (2) E. niger. — Snout and arrangement of scales as before. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 59 luternasal shields three-fourths of the length of the prsefrontals ; frontal two-thirds of the length of the parietals. Colour, black all over. Total length, 420 millimetres ; tail 30. Habitat : Zanzibar. (3) E. hessii. — Snout as in foregoing. Symphysial shield of the lower lip in contact with the anterior chin shields. Colour grey, with black cross-bars ; a series of black spots on the sides, between the bars ; large black blotch on nape ; belly white. Total length, 160 millimetres ; tail 12. Habitat : Congo. (4) E. clecosteri.—'&novii obtusely pointed. Colour, dark grey, each scale edged with black ; belly white. Total length, 380 milhmetres ; tail 38. Habitat : Delagoa Bay. (5) E. sundevallii. — Snout obtusely pointed. Colour reddish-brown, with yellow transverse bands, the scales in which are edged with reddish-brown ; upper lip and belly yellow. Total length, 510 millimetres ; tail 43. Habitat : Caffraria. (6) E. boulengeri. — Scales in 15 rows. Colour black on the back, with narrow white transverse bands ; head white, with a black streak along the parietal suture ; belly blackish-grey. Total length, 170 millimetres ; tail 14. Habitat : Zambesi. (c) Naja. (For the characters of this genus, see Asia, p. 33.) Six species of Naja are found in Africa : — (1) N. liaje or Jiaie. — Scales in 21 — 23 rows on the neck, which is dilatable, although slightly less so than that of IV. tripudians, the Cobra-di-Capello of India. 60 VENOMS Six or seven large supralabial shields, sixth or seventh in con- tact with the lower postocular. Eyes separated from the labial shields by the suboculars. 191—214 ventral scales; 53—64 sub- caiidals. Colour yellowish, olive, or uniform black ; belly yellowish ; black or brown band on the neck ; head sometimes blackish. Total length, 1,180 millimetres; tail 290. Habitat: Borders of the Sahara, Egypt, Southern Palestine, East Africa as far south as Mozambique. Naja haje (the Egyptian Cobra) is common throughout the Nile Basin, the Sudan and Central Africa. Livingstone mentions it several times. In Egypt it is met with in the vicinity of ruined monuments, under the large blocks of stone or among brushwood. The Egyptians are greatly in dread of it, and hunt it down as often as possible. When pursued, N. haje turns bravely and faces its adversary, raising itself upon its tail, puf&ng out its neck and hissing fiercely. If too hard pressed it strikes at its enemy. " A friend of mine," writes Anderson, " had great difficulty in escaping from one of these snakes. While botanising one day a Naja passed quite close to him. My friend darted backwards with all speed, but the Naja pursued and was about to attack him, when he stumbled against an ant-hill and fell flat on his back. This, no doubt, frightened the snake, which disappeared in a twinkling." Another case of the same kind is narrated by Waller, who writes: "A young girl met with her death in a truly dramatic fashion. She was walking behind some porters on a narrow path, when suddenly an Aspic came out of a thick bush, attacked and bit her in the thigh ; in spite of all efforts to save her the unfortunate girl died in less than ten minutes." This instance, which is abso- lutely authentic, proves the truth of the statements made by various travellers. Natives assert that a full-grown Naja invariably pursues either a man or an animal, however large, when either passes within its range (Brehm). THE PRINCIPAL SPECIES OF POISONOUS SNAKES 61 Snake-charmers, of whom there are many in Egypt, always employ Naja haje for their performances. They know how to capture it, and tear out its fangs by making it bite a bundle of rags. Tliis species rarely lives more than six or eight months in captivity, and is quite untamable. It is fond of bathing, and remains in the water for hours together. " The Ancient Egyptians," write Dumeril and Bibron,^ " are known to have worshipped the Naja, which they regarded as the protector of their crops. They allowed it to live and multiply among the cultivated lands, which they apparently entrusted to the care of their tutelary guardian, recognising that this snake freed them from the ravages of the rats, the immense number of which otherwise caused terrible destruction and even actual famine. It was, therefore, from motives of gratitude that the Egyptian Cobra was venerated in this way ; that its image was hung up in the temples ; that its skin was embalmed ; and that its effigy, so easy to recognise and to reproduce roughly, was graven or sculptured on the stones of their monuments. This is the explanation of the fact that paint- ings representing N. haje are frequently reproduced in hieroglyphics and on Egyptian sarcophagi." The Naja was the tutelary deity of the temples, whose duty was to prevent the profane from entering. Thus, in one of the crypts of Denderah we find represented Serpent-genie, figures with a head like that of a Naja supported by the body of a man, with the hands armed with enormous cutlasses (Mariette, Denderah, p. 91, 1875). (2) N. flava. — Same arrangement of scales. Neck dilatable. 200 — 227 ventrals ; 50—67 subcaudals. Colour very variable, yellowish, reddish, brown, or black, uniform or with light spots ; sometimes a black transverse band on the neck. Total length, 1,470 millimetres ; tail 230. Habitat .- South Africa. Erpdtologie generate, t. vii. 62 VENOMS (3) N. melanoleuca.—Co]ova.tion very variable. Sides of the head yellow or whitish ; labial shields tinged with black on the posterior edge. Total length, 2,400 millimetres ; tail 400. Habitat : Tropical Africa. (4) N. nigricoUis.— Third supralabial shield the deepest, sixth and seventh not in contact with the postoculars ; 183—228 ventral scales ; 55 — 68 subcaudals. Coloration very variable ; lower surface of the neck with a black transverse bar. Total length, 2,000 millimetres ; tail 300. Habitat : From Senegambia and Upper Egypt to Angola and the Transvaal. (5) N. anchieta. — Scales in 17 rows on the neck and on the body ; 181—192 ventrals ; 52—62 subcaudals. Colour blackish or brown above ; end of snout and cheeks yellow ; belly yellow or pale brown, with or without black cross-bar under the neck. Total length, 1,800 millimetres ; tail 340. Habitat : Angola and Ovamboland. (6) N. goldii.—'Eyes large, two-thirds the length of the snout in adults. Scales in 15 rows on the neck and on the body ; 194 — 195 ventrals ; 88 subcaudals. Colour black, uniform, or with transverse series of small whitish spots ; cheeks and end of snout white, with a black border at the margin of the shields ; belly white in front, black behind ; sub- caudal scales black. Total length, 1,750 millimetres. Habitat : Lower Niger. (d) Sepedon. Maxillary bones projecting considerably beyond the palatines, with a pair of large poison-fangs ; no other maxillary teeth. Head not distinct from neck ; eyes of moderate size, with round pupils ; THE PRINCIPAL SPECIES OF POISONOUS SNAKES 63 nostril between two nasal shields and an internasal. Body cylin- drical ; scales oblique, keeled, in 19 rows ; ventrals rounded. Tail moderate ; subcaudal scales in 2 rows. S. hcemachates (The Spitting Snake, or Eing Hals Slang). — This snake, which is about 700 millimetres in length, is of a bluish- brown colour, with numerous narrow, undulating and denticulate cross-bands of yellow or yellowish-white. The throat is black or dark red ; the belly grey. It is met with throughout West, East, and South Africa, as far as the Cape of Good Hope, where it is very common. It lives among bushes in sandy places, where the ground is full of the holes of rats, moles, and small rodents, upon which it feeds. It is very active and exhibits great ferocity. Natives at the Cape declare that this snake is able to project its venom to a distance of more than a yard, especially if the wind is blowing in the same direction, and that, if the poison happens to enter the eye, the inflammation that results therefrom often leads to loss of sight (Smith). As to this, a very definite statement is given by Bavay,^ on the authority of Le Naour : — "While hunting in Dahomey," wrote Le Naour to Bavay, "I thrice met with the snake called the Spitter. On two occa- sions my dog was struck in both eyes by the liquid projected by the reptile. Immediately (less than two minutes afterwards), symptoms of conjunctivitis manifested themselves, with consider- able swelling of the pupils; the conjunctivitis seemed as though it were going to be very serious, and yielded only after twelve ' " Le serpent cracheur de la cote occidentale d'Afrique," Societe Zool. de Fra-nce, 1895, p. 210. Bavay thinks that the Spitting Snake is a Naja haje, but the description that he gives of the head of the reptile, which was sent to him by Le Naour, certainly agrees with the characters of Sepeclon. Moreover, I have satisfied myself that the many specimens of Naja haje that I have kept in captivity in my laboratory never possessed the faculty of spitting their poison to a distance. 64 VENOMS days' treatment with boracic lotion, aided by a few cauterisations with sulphate of copper. " During my sojourn at Porto-Novo, a store-keeper at the Dogba trading station was a victim of the Spitter. While working at his store he received in his eye a jet of liquid, which produced violent conjunctivitis." (e) Aspidelaps. Maxillary bones extending forwards beyond the palatines, as in Sepedon, with a pair of large poison-fangs ; no other maxillary teeth. Head slightly distinct from the neck. Eyes of moderate size, with round or vertically elliptic pupils. Kostral shield very large, detached on the sides. Body cylindrical; scales obhque, smooth or keeled, in 19 — 23 rows ; ventrals rounded. Tail short, obtuse ; subcaudal scales in 2 rows. (1) A. luhricus. — 146 — 167 ventral scales; 20 — 28 subcaudals. Colour orange or red, with black rings ; a black bar below the eyes ; upper surface of head sometimes entirely black. Total length, 590 millimetres ; tail 55. Habitat : Cape Colony and Namaqualand. (2) A. scutatus (Fula-fula of Mozambique). — 115 — 135 ventrals ; 24 — 38 subcaudals. Colour pale grey, with black spots or cross-bars, and a black mark shaped like a circumflex accent on the head. A black collar encircling the neck, and a black vertical streak below the eye. Belly whitish. The total length may be as much as 520 millimetres. Habitat : Natal, Delagoa Bay, Mozambique. (f) Walterinnesia. Maxillary bones prolonged forwards beyond the palatines, with a pair of large poison-fangs; no other maxillary teeth. Head distinct from the neck ; eyes rather small, with round pupils ; THE PRINCIPAL SPECIES OF POISONOUS SNAKES 65 nostril between two ov three nasal shields and the internasal. Body cylindrical ; scales smooth or feebly keeled, in 23 rows ; ventrals rounded. Tail rather short ; subcaudal scales for the most part in 2 rows. W. cegyptia. — Colour blackish-brown on the back, paler on the belly. Total length, 1,170 millimetres ; tail 170. Habitat : Egypt. Fig. 34.— Skull of Dendraspis viridis (Poisonous West African Colubrine). (After G. A. Boulenger, op. cit.) (g) Dendraspis. (Fig. 34.) Maxillary bone curved upwards, bearing a pair of powerful poison-fangs, not fissured, and not followed by other teeth ; a 5 60 VENOMS long tooth at the end of each ramus of the mandible. Head narrow, elongate ; eye moderate, with round pupil ; nostril between two shields. Body slightly compressed ; scales smooth, narrow, very obhque, in 13—23 rows ; ventrals rounded. Tail long ; sub- caudals in 2 rows. (1) D. viridis.— 211— 225 veritral scales ; 107—119 subcaudals. Colour uniform olive-green. Shields on the head edged with black ; hps yellow ; belly and tail yellow, with scales and shields bordered with black. Total length, 1,830 millimetres ; tail 4B0. Habitat: West Africa, from the Senegal to the Niger; St. Thome Island. (2) D. jamesonii.—Co\oi'a,tion as before. Scales in 15—19 rows (19—21 on the neck); 210—235 ventrals; 99—121 subcaudals. Tail sometimes black. Total length, 2,100 millimetres; tail 560. Habitat: West Africa, from the Niger to Angola; Central Africa. (3) D. angusticeps (The Mamba).— 2a2— 270 ventral scales; 99 — 121 subcaudals. Colour green, olive, or blackish, uniform; belly yellowish or pale green ; caudal scales and shields not bordered with black. Total length, 2,000 millimetres ; tail 430. Habitat : West Africa, south of the Congo ; Central Africa, East Africa, Transvaal, Natal. (4) D. ajitinorii.— Scales in 21 — 23 rows ; 248 ventrals ; 117 subcaudals. Colour olive on the back, yellowish on the belly. Total length, 2,690 millimetres ; tail 545. Habitat : Ahjssima,. II. — ViPERIDiE. The African Viperidce all belong to the Subfamily Viperince, of which the following are the seven principal genera : — THE PRINCIPAL SPECIES OF POISONOUS SNAKES 67 (a) Causus. (b) Vipera. (c) Bitis. (d) Cerastes. (e) Echis. (f) Atheris. (g) Atractaspis. (a) Causus. (Fig. 35.) Head distinct from the neck, covered with symmetrical shields ; nostril between two nasal shields, and the internasal ; eyes moderate, with round pupils, separated from the lips by subocular shields. Body cylindrical ; scales smooth or keeled, oblique on the sides, in 15 — 22 rows ; ventral scales rounded. Tail short ; subcaudals in 2 rows or single. Four species : — (1) G. rhomheatus. — Snout obtuse, moderately prominent. Scales in 17—21 rows ; 120 — 15-5 ventrals ; 15 — 29 subcaudals. Colour olive or pale brown, usually with a series of V-shaped brown spots bordered with white, and a large spot in the form of a circumflex accent at the back of the head ; lips bordered with black ; belly yellowish or grey. Total length, 700 milhmetres ; tail 75. Habitat : Tropical and South Africa, from the Gambia to the Cape. (2) G. resimus. — Snout prominent, more or less turned up; scales in 19 — 22 rows ; 134 — 152 ventrals ; 17 — 25 subcaudals. Colour_greyish-olive on the back ; uniform white on the belly. Total length, 470 millimetres ; tail 40. Habitat : Central and East Africa, Angola. (3) G. defilijni— 'Snout prominent, more or less turned up. Scales in 17 rows ; 113 — 125 ventrals ; 10 — 18 subcaudals. 68 VENOMS Colour gi-ey or pale brown above, with a series of large rbom- boidal or V-shaped blackish-brown spots; a large A-shaped dark brown mark on the occiput; an oblique dark streak behind the eye ; supralabial shields edged with black ; belly yellowish. Total length, 400 millimetres ; tail 22. Habitat: Central and East Africa, Transvaal. Pig. 35. — Skdll of Causus rhombcatus. (After G. A. Bouleuger, op. cit.) (4) C. lichtensteinii. — Snout obtuse ; scales in 15 rows ; 142 — 144 ventrals ; subcaudals 15 — 21, single. Colour greyish, with rather indistinct darker chevron-shaped cross-bands. Total length, 413 millimetres ; tail 35. Habitat : West Africa (Gold Coast), Congo. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 69 (b) Yipera. (For the characters of this genus, see p. 23, — Europe.) In North Africa are found Vipera latastii, V. ammodytes, and especially F. lebetina, the range of which extends from Morocco to Northern India. Vipera superciliaris, which occurs on the coast of Mozamhique, has the snout rounded, and the head covered -with small, imbricate, keeled scales, with a large supraocular shield ; nostril very large, between two nasal shields ; scales on the body strongly keeled, in 27 rows ; 142 ventrals ; 40 subcaudals. The colour is pale reddish-brown or orange, with blackish trans- verse bars broken by a longitudinal yellow band on each side ; the belly is white, spotted with black. Total length, 570 milhmetres ; tail 77. (c) Bitis. (Fig. 36.) The ViperidcB belonging to this genus have the head very distinct from the neck, covered with small imbricate scales ; the eyes rather small, with vertical pupils, separated from the lips by small scales ; the nostrils directed upwards and outwards, usually pierced in a single nasal shield, with a rather deep pit above, closed by a valvular supranasal. The postfrontal bones are very large, in contact with the ectopterygoids. Scales keeled, with apical pits, in 22 — 41 rows ; ventrals rounded. Tail very short ; subcaudal scales in 2 rows. (1) B. arietans (the Puff Adder ; fig. 37). — This viper has the nostrils on the upper surface of the snout, and two series of scales between the supranasal shields ; 12 — 16 supralabials ; 3 — 5 lower labials. The scales on the body are in 29—41 rows, and strongly keeled ; ventrals 181—145 ; subcaudals 16 — 34. The body is thick, the head large and triangular, and the tail very short. The colour is dirty yellow or orange, with large, 70 VENOMS transverse or oblique, chevron-shaped black bands; an obHque black band extends behind the eye. The belly is dirty yellow, uniform, or marked vi'ith small black spots. Total length, 1,350 millimetres, sometimes more ; tail 160. Fig. 36. — Skull of Bitis arietans (the PuS Adder). (After G. A. Boulenger, op. cit.) Habitat : This snake is met with throughout Africa, from Southern Morocco, Kordofan, and Somaliland, to the Cape of Good Hope, and also in Southern Arabia. It is especially common near the Niger and on the Congo. When irritated, it puffs itself out to such an extent that its THE PBINCIPAL SPECIES OF POISONOUS SNAKES 71 body becomes twice the ordinary size. It then doubles back its head and neck in the shape of an S, and emits a loud and prolonged hiss. Before biting, it first strikes a blow with its head Fig. S7.—BUis arietans (the PufE Adder). (After Dumdril and Bibron. as with a battering-ram, thus justifying its French name, vipdre heurtante (Striking Viper). The natives of South Africa assert that this Viper is able to ^'^ VENOMS spring high enough to strike a rider on horseback. It feeds upon rats and mice, in search of which it often approaches habitations. The Hottentots hunt it in order to obtain its venom; they pound its head between stones, and mix the pulp with the juice of certain plants for the purpose of poisoning their arrows. It lives for a fairly long time in captivity. At the Pasteur Institute at Lille I have succeeded in keeping one of these snakes for two years, feeding it by forcing milk and eggs down its throat. (•2) B. peringueyi. —'t^ostiih opening upwards and outwards. Head covered with small, strongly keeled scales, which are smallest on the vertex ; 11 scales round the eye ; 8 series of scales between the eye and the lip; 11—14 supralabials. Scales on the body in 25—27 rows, strongly keeled ; 130—132 ventrals ; 19—28 sub- ■caudals. Colour greyish-olive, with 3 longitudinal series of grey or blackish spots ; head sometimes with a trident-shaped dark mark, followed by a cross ; under surface whitish, with small dark spots. Total length, 325 millimetres ; ' tail 26. Habitat: Angola and Damaraland. (3) B. at ropos. —'Nostrils opening upwards and outwards, 13—16 scales round the eye; 2—5 series of scales between the supra- nasals ; 10—12 supralabials ; 3—4 infralabials. Scales on the body in 29—31 rows, all strongly keeled ; 124—145 ventrals ; 18—29 subcaudals. Colour brown or grey-brown, with 4 longitudinal series of dark spots, edged with black and white ; two large black marks on the head ; belly grey or brown, with darker spots. Total length, 350 millimetres ; tail 25. Habitat: Cape of G-ood Hope. (4) B. inornata. — Eyes smaller than in B. atropos, and separated from the lips by 4 series of scales ; supraorbital region raised, but without erect horn-like scales ; 15—17 scales across the head ; 13 — 14 supralabials ; 3 lower labials. Scales on the body in 27—29 rows, all keeled ; 126—140 ventrals ; 19—26 subcaudals. THE PBINCIPAL SPECIES OF POISONOUS SNAKES Total length, 350 millimetres ; tail 80. Habitat : Cape of Good Hope. (5) B. cornuta (fig. 38). — Nostrils opening upwards and out- wards. Head covered with small, imbricate, strongly keeled scales ; 2 — 5 raised scales, like horns, above each eye ; 12 — 14 scales round the eye ; 12—15 supralabials ; 2—3 infralabials. Scales on the body keeled, in 25—29 rows; 120—152 ventrals ; 18—36 subcaudals. Colour grey or reddish - brown, with black spots, edged with white and arranged in 3 or 4 longitudinal series ; a dark, oblique streak from the eye to the mouth ; belly yellow or brown, uniform or spotted. Total length, 510 milHmetreS ; (After Dumeril and Bibron.) tail 35. Habitat : Cape Colony, Namaqualand, Damaraland. (6) B. caudalis. — Nostrils opening upwards and outwards. 12 — 16 scales from one eye to the other across the head ; above each eye a single, erect, horn-like scale ; 10 — 16 scales round the eye ; 10 — 13 supralabials ; 2 — 3 infralabials. Scales on the body in 22 — 29 rows, strongly keeled ; 112—153 ventrals ; 18 — 33 sub- caudals. Colo;ir reddish or sandy-grey, with 2 series of brown spots with light centres, and frequently a vertebral series of narrow spots ; belly dull yellow, uniform, or with small black spots on the sides. Total length, 360 millimetres ; tail 25. Habitat: South-west Africa, from Angola to Namaqualand. (7) B. gabonica (Gaboon Viper, or Kiver Jack Viper). — Nostrils directed upwards and outwards. Head covered with small, moderately keeled scales, smallest on the vertex, 13 — 16 from eye to eye ; 15 — 19 scales round the eye ; a pair of erectile, triangular, nasal " horns," consisting of sometimes tricuspid shields, between the supranasals ; 13 — 16 supralabials ; 4—5 infralabials. Scales 74 VENOMS on the body in 33 — 41 rows, strongly keeled ; lateral scales slightly oblique ; 125—140 ventrals ; 17—83 subcaudals. This viper, which often attains a length of 1,200 millimetres is brown, with a vertebral series of quadrangular, yellowish, or light brown spots connected by black markings ; the belly is dull yellow, with small brown or blackish spots. Habitat: Tropical Africa (West Africa, from Liberia to Damara- land ; Zanzibar, Mozambique). This species, which is nocturnal, is often met with on the Gaboon, and in the forests near the banks of the Ogowai. Its head is enormous, triangular in shape, and wider above; it has a bulky body, and a very short tail, terminating abruptly in a point. The Gaboon Viper is a savage snake, with very active venom, and its poison-glands are of the size of large almonds. It lives in virgin forests, among dead wood and rocks. I have several times met with it in manioc plantations on the edge of the woods. In broad daylight it is sluggish, moves somewhat slowly, and never attacks man. It bites only when surprised. (8) B. nasicornis (fig. 39). — Nostrils opening upwards and outwards. Head covered with, small strongly keeled scales, smaller on the vertex, 14 — 16 from one eye to the other ; 2 or 8 pairs of com- pressed, erectile, horn - like shields between the supra- FiG. 39.— Bitis nasicornis. nasals, usually Separated in (After Dumerii and Bibron.) the middle by 1 or 2 Series of small scales ; 15 — 18 supra- labials ; 4 — 6 infralabials. Scales on the body in 35 — 41 rows, strongly keeled ; 124 — 140 ventrals ; 16 — 32 subcaudals. Colour purple or reddish-brown above, with pale olive or dark THE FBINCIFAL SPECIES OF POISONOUS SNAKES 75 brown spots ; a vertebral series of brown, black-edged spots, wbich assume a rhomboidal form ; sides of head dark brown, with a triangular light mark in front of the eye, and an oblique light streak, from behind the eye to the mouth ; belly pale olive, spotted with black or yellow. Total length, 1,250 millimetres ; tail 125. Habitat: West Africa, from Liberia to the Gaboon. (d) Cerastes. Head very distinct from the neck, covered with small juxta- posed or slightly imbricate scales ; eyes small, with vertical pupils, separated from the lips by small scales ; nostrils opening upwards and outwards. Body cylindrical ; scales keeled, with apical pits, in 23 — 35 rows. Tail short ; subcaudals in 2 rows. (1) C. cornutus (fig. 40). — Snout very short and broad ; two erectile horns above the eyes, which are separated by 15 — 21 scales and surrounded by 14 — 18 ; 4 — 5 series of scales betw^een the eyes and the lips ; 12 — 15 supralabials ; 3 infralabials ; scales on the body in 27 — 35 rows ; 130 — 165 ventrals ; 25 — 42 subcaudals. Colour yellowish-brown or grey, with or without brown spots, forming ^Q.- Cerastes comutus. 4 — 6 regular series, the two middle ones (After Dumerii and Bibron.) sometimes forming cross-bars ; an ob- lique dark streak behind the eye ; belly white ; end of tail some- times black. Total length, 720 millimetres; tail 90. Habitat : Northern border of the Sahara, Egypt, Nubia, Arabia, and Southern Palestine. (2) C. vipera. — Snout very short and broad ; head covered with small, tubercularly keeled scales, to the number of 9 — 13 from eye to eye ; no " horns "; 9 — 14 scales round the eye ; nostril between 76 VEl^OMS two small shields, separated from their neighbours by 0 — 0 series of scales ; 10 — 12 supralabials ; 8 infralabials. Scales on the body in 23—27 rows ; 102 — 122 ventrals, rather strongly keeled at the sides ; 18 — 26 subcaudals. Colour dull yellow, pale brown or red- dish, with or without black spots ; end of tail often black above ; ventral surface white. Total length, 340 millimetres ; tail 30. Habitat: Northern border of the Sahara, from Algeria to Egypt. The snakes belonging to this genus live constantly hidden in the sand, lying in wait for small birds, which alight beside them with- out suspicion, mistaking their horns for insects or larvae ; they also feed upon mice. Their poison-fangs are of relatively large size. These small and exceedingly active vipers, whose colour har- monises marvellously with their surroundings, are very dangerous to the Arabs and blacks, who walk barefooted; they frequently cause fatal accidents. They are able to exist for a very long time without drinking. They are attracted by the fires which are lighted at night round caravan encampments. (e) Echis. (See Asia, p. 48.) (1) E. carinatus (Efa, Viper of the Pyramids). — The same as met with in Persia, Arabia, and India. Very common in the environs of Cairo, and throughout Egypt and Abyssinia. It often makes its way into towns and villages. Brehm records that he more than once found an Efa in his house at Khartoum, and that on one occasion he discovered one of these vipers coiled up beneath the covering of his bed. At another time, getting up in the night, he put his foot on one of these animals and was not bitten, the reptile being very fortunately just at that moment in the act of devouring a tame bird which it had seized. It hardly ever happens that a native of Egypt can bring THE PBINCIPAL -SPECIES OF POISONOUS SNAKES 77 himself to destroy an Efa, of which he has the greatest dread. If, as often occurs, he finds one of these reptiles in his house, he addresses himself to the Hani or juggler, in order that, by his magic art, he may expel the dangerous visitor. From this custom the juggler evidently derives no small advantage, for, as is only right, he does not ply his craft for nothing. In many cases, indeed, the juggler releases a snake in a house, and then goes and informs the owner that he knows that a reptile is concealed in his dwelling, and that, in consideration of a stipulated reward, he will rid him of it (Brehm). Fig. 41. — Echis coloratiis. (After G. A. Boulenger, op cit.) (2) E. coloratus (fig. 41). — Scales on the snout and vertex convex, smooth or bluntly keeled, 13 — 15 from eye to eye ; no supraocular shield ; 17 — 22 scales round the eye ; 12—15 supra- labials ; scales on the body in 31 — 35 rows ; 174 — 205 ventrals ; 42 — 52 subcaudals. No cruciform mark on the head. Total length, 750 millimetres ; tail 80. Habitat: Palestine, Arabia, Socotra. 78 VENOMS (f) Atheris. Head wevy distinct "from neck, covered with imbricate scales; eyes large, with vertical pupils, usually separated from the labial shields by small scales; nostrils lateral. Body slightly compressed ; scales keeled, with apical pits. Tail moderate, prehensile ; sub- caudal scales in a single row. (1) A. chlorechis. — No supraciliary horn-like scales; 9 — 11 scales from eye to eye ; 25 — 36 rows of scales in the middle of the body, strongly keeled ; 154 — 165ventrals; 53 — (32 subcaudals. Colour green,, uniform or with small yellow spots; end of tail yellowish or blackish. Total length, 520 millimetres; tail 85. Habitat : West Africa, from Liberia to the Ogowai. (2) A. squamiger. — No supraciliary horn-like scales ; 7 — 8 scales from eye to eye ; 15 — 25 rows of scales in the middle of the body, strongly keeled ; 153 — 173 ventrals ; 51 — 95 subcaudals. Colour olive, uniform or with more or less regular, narrow 5'ellow cross-bands, or yellow with green spots ; belly pale olive, marbled with black or yellow, or uniform yellow. Total length, 550 millimetres ; tail 100. Habitat : West Africa, from the Cameroons to Angola. (3) A. ceratophorus. — Several erect, supraciliary horn-like scales ; 9 — 10 scales from eye to eye ; 25 rows of scales in the middle of the body, strongly keeled ; 142 ventrals ; 55 subcaudals. Colour dark olive, with black spots forming cross-bands ; belly pale olive, speckled with black. Total length, 210 millimetres ; tail 65. Habitat : East Africa. (g) Atractaspis. (Fig. 42.) This genus is characterised by enormous poison-fangs, a few teeth on the palatines, and none on the pterygoids. The mandible, which is edentulous in front, has only two or three small teeth in THE PRINCIPAL SPECIES OF POISONOUS SNAKES the middle of the dentary bone. Head small, not distinct from the neck, covered with large symmetrical shields ; nostril between two nasal shields; eyes minute, with round pupils; postfrontal bone absent. Body cylindrical ; scales smooth, in 17 — 37 rows ; ventrals rounded. Tail short ; subcaudals in 1 or 2 rows. (1) A. hildehrandtii. — Six supralabials ; no praeocular shields; frontal shorter than the parietals ; scales on the body in 17 rows ; ventrals 167—174. Colour uniform dark brown. Total length, 450 millimetres; tail 53. Habitat : East Africa. (2) A. congica. — Five supralabials, of which the fourth is the larger ; postocu- lar in contact with a large temporal ; one praeocular ; frontal as long as or slightly shorter than the parietals. Scales on the body in 19—21 rows; 209— 230 ven- trals ; 19 — 23 sub-caudals. Colour uniform dark brown or black. Total length, 450 millimetres ; tail 35. Habitat : Congo, Angola. (3) A. irregularis. — Characters as before, but scales on the body in 25—27 rows ; 220—257 ventrals , subcaudals 22—28 pairs. Col our uniform black or dark brown. Total length, 560 millimetres ; tail 35. Fig. 42. — Skold of Atractaspis aterrima (African Viperine). (Afber G. A. Boulenger, 07;. cit.) . 80 VENOMS Habitat: West Africa, from the Gold Coast to the Congo; Central Africa. (4) A. corpideiita. — Postocular shield in contact with a large temporal; second lower labial very large, fused with the chin- shields. Scales on the body in 23—27 rows ; 178—198 ventrals ; 23 — 27 subcaudals. Colour uniform blackish-brown; tail sometimes white. Total length, 345 millimetres ; tail 33. Habitat : West Africa, from Liberia to the Gaboon. (5) A. rostmta. — Snout very prominent, cuneiform. Third lower labial very large ; first lower labial in contact with its fellow, behind the symphysial. Scales on the body in 19 — 23 rows ; ven- trals 227—248. Colour uniform dark brown, or blackish. Total length, 600 millimetres ; tail 37. Habitat : East and Central Africa. (6) A. bibronii. — Characters as before. Snout prominent, sub- cuneiform. Ventral scales, 221 — 260. Colour dark purplish-brown above, dull yellow or pale brown on the belly. Total length, -600 millimetres ; tail 25. Habitat: Eastern districts of Cape Colony, Natal, Namaqua- land, Angola. (7) ^. aterrima. — Characters as before. Snout rounded; 251 — 300 ventral scales. Colour uniform dark brown or black. Total length, 650 millimetres ; tail 30. Habitat : West and Central Africa. (8) A. claliomeyensis. — Characters as before. Symphysial shield in contact with the chin-shields. Scales on the body in 31 rows ; 240 ventrals ; 24 subcaudals. Colour black above, brown on the belly. Total length, 490 millimetres ; tail 32. Habitat : Dahomey. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 81 (9) A. micropJtolis.—Tem.Tpmcal shields small, '2 + 3 or 4 ; fourth or fifth infralabial larger ; scales on the body in 25 rows ; 210 — 215 ventrals; 29 — 30 subcaudals. Frontal shield slightly longer than broad, much longer than the parietals. Colour uniform dark brown. Total length, 330 millimetres ; tail 28. Habitat : Cape Verd. (10) A. leucomelas. — Characters as before. Frontal one and two-fifths as long as broad, as long as the parietals. Colour black, with a vertebral white line, occupying one row and two half rows of scales ; ventrals and subcaudals white ; neck black, head white, with a black spot covering the nasals and upper head-shields. Total length, 575 millimetres; tail 40. Habitat : Somaliland. (11) A. microlepidota . — Characters as before. Scales on the body in 29—37 rows ; 212—245 ventrals ; 26—37 subcaudals. Colour uniform dark brown. Total length, 540 millimetres ; tail 45. Habitat : Central and East Africa. D.— AUSTRALIA AND THE LABGE ADJACENT ISLANDS. The Sunda Islands and the whole of Malaysia are rich in poisonous snakes. Those that are found there belong for the most part to species that we have already met with in India or the Malay Peninsula. We shall therefore not describe them again here. All those that inhabit Australia are included in the great Family CoLUBRiDiE and the Subfamily Elapin^. There are no Viperid^ ; but certain genera of poisonous Colubrid^ are peculiar to this continent. These reptiles have been particularly well studied by Gerard 6 82 VENOMS Krefft, formerly Director of the Australian Museum at Sydney, from whose work ' we shall borrow a considerable portion of the following notes, and the figures accompanying them. The genera represented in Australia are : — (a) Ogniodon. (b) Glypliodon. (c) Pseiulelaps. (d) Diemenia. (e) Pseuclechis. (f) Denisonia. (g) Micropechis. (h) Hopiloceplialus. (i) Tropidechis. (j) Notechis. (k) Bhinlioplocephalus. (1) Brachyaspis. (m) AcantJiopJiis. (n) Elapognathus. (o) Bhynclielaps. (p) Furina. (a) Ogmodon. This genus is characterised by the maxillar}^ bones extending forwards as far as the palatines, and bearing, in addition to the poison-fangs, 6 — 7 grooved teeth. The head is not distinct from the neck ; the eyes are very small. The body is cylindrical, and covered with smooth scales in 17 rows. Tail short ; subcaudal scales in 2 rows. 0. vitianus. — Snout elongate, pointed ; 139 — 15'2 ventral scales ; 27 — 38 subcaudals. ' " The Snakes of Australia," Sydney, 1869. THE PRINCIPAL SPECIES OF POISONOUS SNAKES 83 Colour dark brown, lighter on the sides; belly brown or white, more or less spotted with black ; tail black. Total length, 360 millimetres ; tail 45. Habitat : Fiji Islands. Fig. 43. — Skoll of Glyphodon iristis (Australian Colubriue). (After G. A. Boulenger, qp. cit.) (b) Glyphodon. General characters the same ; snout rounded ; poison-fangs followed, after a wide interspace, by (3 small grooved teeth ; anterior mandibular teeth strongly developed (fig. 43). Head and 84 VENOMS eyes small ; pupils round or vertically subelliptic ; nostrils pierced between 2 nasal shields. Body cylindrical ; scales smooth, in 17 rows ; tail short ; subcaudals in 2 rows. G. tristis. — ^Ventral s.cales 165—179 ; subcaudals 38—52. Colour dark brown; occiput often yellowish, or pale reddish- brown ; belly yellow. Total length, 900 millimetres ; tail 125. Habitat : North-eastern Australia and South-eastern Xew Guinea. ■ (c) Pseudelaps. Maxillaries extending forwards as far as the palatines, with a pair of large grooved poison-fangs, and, after a wide interval, 8—12 small grooved teeth. The anterior mandibular teeth are of large size, almost like fangs. Head hardly distinct from the neck ; eyes small, with vertically elliptic pupils. Body cylindrical ; scales smooth, in 15 — 17 rows. Tail moderate or short ; sub- caudal scales in 2 rows. (1) P. muelleri. — Scales in 15 rows. Nasal shield divided, in contact with the prseocular ; 2 -|- 2 temporals ; 139 — 17(5 ventral scales ; 21 — 35 subcaudals. Colour brown, with a light vertebral line ; a more or less distinct dark, light-edged streak on each side of the head, passing through the eye ; belly yellowish or coral-red^ uniform or spotted with black. Total length, 500 millimetres ; tail 70. Habitat : Moluccas, New Guinea, New Britain. (2) P. squamulosus. — Scales in 15 rows. Nasal shield divided, in contact with the prseocular ; 1 4- 2 temporals ; 170 — 183 ventrals ; 34 — 52 subcaudals. Colour brown, with a yellowish streak round the snout and through the eyes to the nape ; belly whitish, with confluent black spots forming lines on each side. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 85 Fig. 44. — Pseudelaps krefftii. Total length, 375 millimetres ; tail 55. Habitat : New South Wales. (3) P. Jcrefftii (fig. 44). — Nasal shield entire, in contact with the piEBOCular; 1 + 2 temporals ; 14G— 156 ventrals ; 26— 38 subcaudals. Colour dark brown, with a light longitudinal line on each scale ; a yellowish cross-band on the occiput, connected with another yellow band which encircles the snout. Belly yellowish in front, black behind; subcaudals white, with a longitudinal black band running be- tween them. Total length, 255 millimetres ; tail 33. Habitat : Queensland. (4) P. harriettcB (fig. 45). — Nasal shield entire, in contact with or narrowly separated from the pree- ocular; 1 -f 2 temporals ; 176 — 193 ventrals ; 29 — 35 subcaudals. Colour dark brown, with a light longitudinal line on each scale ; a long yellow blotch on the nape, and, connected with this, a yellow ring round the snout ; ventrals and sub- caudals brown or black, edged with white. Total length, 415 millimetres ; tail 45. Habitat : Queensland. (5) P. cliadema (fig. 46).— Nasal shield entire, widely separated from the prseocular ; 2 -f 2 temporals ; third and fourth upper labials entering the eye; 164—203 ventrals; 40—62 subcaudals. Colour pale brown or reddish, with a brown edging to each scale forming a reticulate pattern; a yellow cross-band on the occiput; belly uniformly white. Total length, 600 millimetres ; tail 80. Fig. 45. — Pseudelaps liarrietta. Fig. 46. —Pseudelaps diadema. VENOMS Habitat : Eastern, Northern, and Western Australia. ((5) P. «far/-o.— Characters the same as in the previous species ; 143 ventrals. Colour brown ; a broad lunate black collar on the nape ; head black above, but paler than the collar. Habitat : Port Curtis, Queensland. (7) P. sutherlancli. — Characters as before. Scales on the body in 17 rows; KiO ventrals; 40 subcaudals. Colour red-brown on the back, yellow on the belly ; a broad lunate black collar on the nape, with a lighter edging ; light bars across the head, body, and tail. Habitat: Norman Eiver, Queensland. (cl) Diemenia. Maxillary bones extending forwards as far as the pala- tines, with a pair of large grooved poison-fangs, followed, after an interspace, by 7 — 15 small grooved teeth ; anterior mandibular teeth much elon- gated, resembling poison-fangs- Head scarcely distinct from the neck ; eyes rather large, with round pupils ; nasal shield entire or divided ; frontal elongate. Body cylindrical; scales smooth, in 15 — 19 rows (more on the neck). Tail moderate or long ; subcaudals all or for the most part in 2 rows. Coloration very variable, orange-3'ellow, olive, red-brown, or pale brown. Average length, 1,000 — 1,700 millimetres. Habitat : South-eastern New Guinea, and Australia. Fig. 47. — Dicmcnia psammopliis. Fig. iS.—Diciiicnia olivacea (Northern Australia and New Guinea). (After Krefft. ) Fig. 49. — Diemenia textilis. THE PBINCIFAL SPECIES OF POISONOUS SNAKES H7 Seven species of this genus are known, divided into two groups as follows : — i (1) Scales on the body in 15 rows. D. psammophis (fig. 47). — Internasal shields at least half as long as the prsefrontals. D. torquata. — Internasals more than half as long as the prefrontals. D. olivacea (fig. 48). — In- ternasals not more than half as long as the preefrontals ; snout broad. (2) Scales in 17 or 19 rows. D. modesta. — 154 — 165 ventrals. D. textilis (Brown Snake, fig. 49) Pig. 50. — Diemenia nuchalis. -190—232 ventrals. D. nuchalis (fig. 50).— 184— 224 ventrals. (e) Pseudechis. Maxillary bones extending forwards as far as the palatines, with a pan- of large grooved poison-fangs followed by 2 — 5 small solid teeth ; anterior mandibular teeth long. Head distinct from the neck ; eyes rather small, with round pupils ; nostril be- tween two nasal shields. Body cylindrical. Scales smooth, in 17 — 23 rows (more on the neck). Tail moderate ; sub- caudals in 2 rows, or partly single, partly in 2 rows. Total length, 1,500—2,000 millimetres, sometimes more. Habitat : Australia and New Guinea This genus includes eight species. Fig. 51. — Pseudechis porphyriacus. VENOMS (1) P. 2n)rphyriacus (Black Snake; fig. 51).— Frontal shield longer than broad ; 180—200 ventrals ; 50—60 subcaudals. Colour black on the back ; outer row of scales red at the base ; ventrals red, edged with black. (2) P. cupreus.—l'dd—'m ventrals ; 57—72 subcaudals. Colour coppery above, brown or orange below, all the scales and shields edged with brown. (3) P. aus^r«Zi5.— 199— 220 ventrals ; 57—70 subcaudals ; frontal shield once and two-thirds to twice as long as broad. Colour pale brown on the back, yellowish on the belly. (4) P. darioiniensis.—^mnio]. as broad as long; 212 ventrals; 54 — 64 subcaudals. Colour reddish-brown ; head pale brown ; belly yellowish-white. (5) P. papuamis.—^coXes in 19—21 rows (26 or 27 on the neck) ; 221—224 ventrals ; 49—55 subcaudals. Colour uniform black ; chin white. (6) P. scwi;e//a^«s.— Subcaudal shields in 2 rows; scales on the body in 23 rows (25—30 on the neck); 230—233 ventrals; €1 — 78 subcaudals. Colour pale brown or dark brown ; snout and cheeks pale brown or yellowish ; belly yellow. (7) P. niicrolepidotus.~^Q—'d% scales across the neck, 23 across the middle of the body; 232-237 ventrals; 61—66 pairs of sub- caudals. Colour dark brown on the back, yellowish-grey on the belly ; head sometimes blackish. (8) P. /eroa;.— Snout very broadly rounded. Scales on the body in 23 rows ; 235 ventrals ; 60 pairs of subcaudals. Colour black above, yellowish beneath. (f) Denisonia. Maxillary bones prolonged as far as the palatines, with a pair of L-ge grooved poison-fangs, followed by 3—5 small solid teeth; THE FlilNCIFAL SPECIES OE FOISONOUS SNAKES K9 anterior mandibular teeth greatly developed. Head fairly distinct from the body ; eyes small, with round or vertically elliptic pupils ; nasal shield entire or divided. Body cylindrical ; scales smooth, in 15 — 19 rows ; tail moderate or short ; subcaudals in a single row, except in one species. According to the British Museum Catalogue, the genus Denisonia includes twenty- one species, the principal characters of which are as follows : — (1) D. superha (The Cop- perhead. Fig. 52).— Scales in 15 — 17 rows; nasal shield entire, in contact with the prsBOcular ; ventral scales 145 — 160 ; subcaudals 41 — 50. Colour brownish to dark olive on the back, often yellow or salmon-red on the sides ; belly yellowish or greyish-olive. Total length, 1,010 millimetres ; tail 160. Habitat : New South Wales, Southern Australia, Tasmania. (2) D. coronata. — Scales in 15 rows ; 188 — 151 ventrals ; 88 — 51 subcaudals. Colour olive, with a black streak on each side of the head ; belly yellowish or pale olive. Fig. b1.— Denisonia snpcrba (The Copper- head). Fig. 53. — Denisonia coronoides. Total length, 480 millimetres ; tail 95. Habitat: Western Australia and New South Wales. (3) D. coronoides (fig. 53). — Scales in 15 rows ; 136 — 151 ventrals ; 89 — 57 subcaudals. Colour brown, lips yellow ; belly salmon-red to dark olive-grey ; end of tail salmon-red. Total length, 440 millimetres ; tail 80. 90 VENOMS Habitat : Southern Australia and Tasmania. (4) D. inueUeri.— Scales in 17 rows ; 118 ventrals ; 38 sub- caudal s. Colour grey-brown ; lips and chin with yellow spots ; belly grey. Total length, 292 millimetres; tail 52. Habitat : Queensland. (5) D. //•(;/?.« ^a.— Scales in 19 rows ; 1G7 ventrals ; 85 sub- caudals. Colour olive-brown ; upper lip yellow ; belly white. Total length, 390 millimetres ; tail 54. Habitat : Lake Elphinstone, Queensland. (G) D. ramsarji (fig. 54). — Scales in 15 rows ; 164 ventrals ; 51 subcaudals. Colour dark olive -green above, yellow beneath ; subcaudals nearly black. Total length, 265 millimetres ; tail 50. Habitat : New South Wales. (7) D. signata (fig. 55). — Scales in 17 rows ; 158 — 170 ventrals ; 41 — 56 subcaudals. Colour dark olive or black, head brown ; belly dark grey or black. Total length, 640 millimetres ; tail 120. Habitat : Queensland, New South Wales. (8) D. daemelii. — Scales in 17 rows ; 147 — 168 ventrals ; 83 — 45 subcaudals. Colour olive, head darker ; belly yellowish-white. Total length, 880 millimetres ; tail 60. Habitat : Queensland. (9) D. .s«^rt.— Scales in 19 rows ; 157—164 ventrals ; 25—30 subcaudals. Colour pale olive-brown, head dark brown, nape black ; upper lip and belly yellow. Fig. 54. — Denisonia raiiisaiji. Fig. 55. — Denisonia signata. THE FBINCIPAL SPECIES OF POISONOUS SNAKES 91 Total length, '200 millimetres ; tail 28. Habitat : Southern Australia. (10) D. frontalis. — Scales in 19 rows; 154 ventrals ; 30 sub- caudals. Colour light brown, with a vertebral black line ; belly pearly- white, with a median bronze-coloured band. Total length, 400 millimetres ; tail 50. Habitat : New South Wales. (11) D. flagellam. — -Scales in 17 rows ; 132 — 138 ventrals ; 25 — 27 subcaudals. Colour pale brown ; vertex, occiput, and nape black ; upper lip and belly white. Total length, 380 millimetres ; tail 40. Habitat : Victoria. (12) D. maculata (fig. 56). — Scales in 17 rows ; 121—136 ventrals ; 20—30 subcaudals. Colour dark grey-brown, or brown ; a large dark olive-green or brown blotch on the head, with two or three unequal light grey spots ; belly white. Total length, 400 millimetres ; tail 55. Habitat : Queensland. (13) D. punctata. — Scales in 15 rows ; 160 ventrals ; 25 subcaudals. Colour pale brown ; head and nape orange ; upper lip and belly yellow. Total length, 350 millimetres ; tail 36. Habitat : North-Western Australia. (14) D. gouldll (fig. 57). — Scales in 15 rows ; 140 — 170 ventrals ; 22 — 23 subcaudals. Colour brownish-yellow ; nape black ; head covered with a broad greenish-blue blotch, extending from the nose to the neck; upper lip and belly yellow. Fig. 56. — Denisonia maculata. Fig. 57. — Denisonia gouldii. 92 VJiNOMS Total length, 485 millimetres; tail 50. Habitat : Western and Southern Australia. (15) D. nigrescens. — Scales in 15 rows ; 170 — 200 ventrals ; 80 — 40 subcaudals. Colour dark olive ; head black ; belly yellow. Total length, 545 millimetres ; tail 75. Habitat : New South Wales and Queensland. (10) D. nigrostriata. — Scales in 15 rows; 180 — 184 ventrals; 50 — 64 subcaudals. Colour yellow, streaked with black ; head dark brown ; upper lip and belly yellowish-white. Total length, 380 miUimetres ; tail 52. Habitat : Queensland. (17) D. carpentarice. — Scales in 15 rows; 106 — 188 ventrals; 31 — 43 subcaudals. Colour brown ; upper lip and belly yellowish-white. Total length, 285 millimetres ; tail 47. Habitat : Northern Queensland. (18) -D. paUidiceps. — Scales in 15 rows ; 170 — 178 ventrals ; 37 — 38 subcaudals. Colour dark olive-brown ; head somewhat paler ; belly yellowish. Total length, 590 millimetres ; tail 80. Habitat : Northern Australia. (19) D. melanura. — Scales in 15 or 17 rows ; 105 — 171 ventrals ; 38 — 48 subcaudals. Colour dark brown ; head and sides usually reddish ; belly yellow ; tail black. Total length, 1,000 millimetres ; tail 140. Habitat : Solomon Islands. (20) D. par.— Scsiles in 10 rows; 164—166 ventrals; 40—49 subcaudals. Colour reddish-brown, in broad bands with white intervals ; head blackish-brown ; belly white ; tail with red rings. Total length, 750 millimetres ; tail 110. THJ^ PBINCri'AL Sl'KCIES OF roISONOUH SNAKES 93 Habitat : Faro aud Howla Islands, Bougainville Straits, Solomon Islands. (21) D. woodforclii. — Scales in 17 rows ; 1(36 — 172 ventrals ; 41 — 45 subcaudal pairs. Colour brownish-white, with a reticulate pattern; head dark brown ; belly white. Total length, 670 millimetres ; tail 100. Habitat : New Georgia, Solomon Islands. (g) Micropechis. Maxillary bones extending forward as far as the palatines, with a pair of large grooved poison-fangs, followed by three small solid teeth ; mandibular teeth longer m front. Head distinct from the neck; eyes very small, with round pupils; nostril between two nasal shields. Body cylindrical ; scales smooth, in 15 or 17 rows. Tail short ; subcaudals in 2 rows. (1) M. iJi-aheka. — Scales in 15 rows ; 180 — 223 ventrals ; 39 — 55 subcaudals. Colour yellow and black, in irregular cross-bars ; head and tail black above ; belly yellow. Total length, 1,550 miUimetres ; tail 180. Habitat : New Guinea. (2) M. elapoides. — Scales in 17 rows ; 208 ventrals ; 35 sub- caudals. Colour cream, with 22 black bands, broader than the inter- spaces between them ; snout and ocular region black. Total length, 750 millimetres; tail 75. Habitat : Florida Island, Solomon Group. (b) Hoplocephalus. Characters the same as in Micropechis. Scales in 21 rows ; ventrals angulate and notched laterally. Tail moderate ; sub- caudals in a single row. 94 VENOMS (1) H. hungaroides (Syn. H. variegatus. The Broad-headed Snake).— 204— 221 ventrals ; 40—56 subcaudals. Colour black on the back, with yellow spots forming more or less regular cross-bands on the body ; upper lip yellow, margined with black ; belly blackish, yellow on the sides. Total length, 1,G20 millimetres ; tail 210. Habitat : New South Wales. (2) H. hitorquatus (fig. 58).— Ventral scales strongly angulate laterally, 191—227 ; subcaudals 44—59. Colour olive-green ; head pale olive, with a bright yellow occipital blotch, and a large black blotch on each side of the nape ; a pair of small spots in front of and between 'S'-iG. bS.—Hopiocephaiushitorrinatics. the eyes; three black transverse blotches on the vertex ; belly greyish- olive or brown. Total length, 510 milhmetres ; tail 95. Habitat : Queensland, New South Wales. (3) H. stephensii. — 239 ventrals ; 60 subcaudals. Body barred alternately with black and white ; the black bars are twice as broad as the white ones ; head dark, spotted with yellow ; a W-shaped yellow mark on the back of the head. Total length, 760 millimetres. Habitat : Port Macquarie, New South Wales. (i) Tropidechis. Same general characters ; nasal shield entire ; scales on the body strongly keeled, in 23 rows. Tail moderate ; subcaudals in a single row. T. carinaius. — Colour dark olive, with darker cross-bands ; belly yellow, more or less tinged with olive-green. Total length, 730 millimetres; tail 120. Habitat : New South Wales, Queensland. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 95 (j) Notechis. Same general charactei-s ; pupil round ; nasal shield entire. Body cylindrical ; scales smooth, disposed obliquely, in 15 — 19 rows, the lateral scales shorter than the dorsals. Tail moderate ; subcaudals in a single row. N. scutatiis (Syn. Hoploceph- alus curtus. The Tiger Snake. Fig. 59). — Colour dark olive ; belly yellow or olive ; the shields often dark-edged. Total length, 1,280 milli- metres ; tail 170. Fig. b9.—NotecUis sciitatus (The Tiger Habitat: Australia and Tas- ^"^^^^'^ mania. (k) Rhinhoplocephalus. Dentition as in Hoplocephalus. Head but little distinct from the neck ; eyes small, with round pupils ; no internasal shields. Body cylindrical, rigid. Scales smooth, in 15 rows. Tail short ; subcaudals in a single row. B. hicolor. — Colour greyish-olive on the back, yellowish- white on the belly ; tongue white. Total length, 395 millimetres ; tail 55. Habitat : Australia. (1) Brachyaspis. Characters the same, but head distinct from the neck ; eyes small, with vertically elliptic pupils ; nostril between two nasal shields. Body stout, cylindrical ; scales smooth, slightly oblique, in 19 rows. Tail short ; subcaudals in a single row. B. cicrta. — Colour uniform olive-brown ; belly yellowish. 96 VENOMS Total length, 490 millimetres ; tail 70. Habitat : Western Australia. (m) Acanthophis (Death Adder). (Figs. GO, Gl.) Maxillary bones extending forwards as far as the palatines, with a pair of large grooved poison-fangs, followed by two or three small teeth; anterior mandibular teeth elongate, fang-like. Head distinct from the neck ; eyes small, with vertically elliptic pupils ; nostril in the upper part of a single nasal shield. Body stout, Fig. 60. — Skull of Acanthophis antarcticus. (After G. A. Boulenger, oj). cit.) cylindrical. Scales more or less distinctly keeled, in 21 — 23 rows. Tail short, compressed at the end and terminating in a sort of long spine, turned upwards ; anterior subcaudals in a single row, posterior in 2 rows. A . antarcticus (The Death Adder ; fig. 61). — Supraocular shields often raised and angular, assuming the shape of little horns ; scales on the crown of the head rugose and striated ; 113 — 130 ventrals ; 41 — 51 subcaudals (the last 5 — 27 are divided). THE PBINCIPAL SPECIES OF POISONOUS SNAKES 97 Colour yellow-brown or reddish, with more or less distinct dark cross-bands ; black spots or small dark bars on the lips; belly yellowish-white ; end of tail yellow or black, covered with spiny scales. Total length, 850 milli- metres ; tail 150. Habitat : Moluccas, New Fig. GI. —AcanthopMs antarcticns (The Guinea, Australia. Death Adder). (n) Elapognathus. Maxillary bones extending" forwards as far as the palatines, with a pair of moderately large grooved poison-fangs ; no other maxillary teeth ; mandibular teeth subequal. Eyes moderate, with round pupils ; nasal shield entire. Body cylindrical ; scales smooth, in 15 rows ; ventrals rounded ; tail moderate ; subcaudals in a single row. E. minor. — Colour dark olive, with a black occipital blotch in the young ; belly yellow or greenish-grey. Total length, 460 millimetres ; tail 95. Habitat : South-west Australia. (o) Rhynchelaps. Maxillary bones extending forwards as far as the palatines, with a pair of moderately large grooved poison-fangs, and two small teeth near the posterior extremity of the bone ; anterior mandibular teeth the longest. Head small, not distinct from the neck ; eyes small, with vertically elliptic pupils ; nostril in a single nasal shield. Body short, cylindrical ; scales smooth, in 15 — 17 rows. Tail very short ; subcaudals in 2 rows. (1) B. hertholcU.—^icales in 15 rows ; 112—126 ventrals. 7 98 VENOMS Colour yellow, with 19—40 black annuli, usually narrower than the interspaces ; head brown, with a large black blotch on the nape, and another on the vertex and temples. Total length, 270 mihimetres ; tail 22. Habitat: Southern and Western Australia. (2) li. austmlis (fig. 62). — Scales in 17 rows ; 152 — 163 ventrals; 18 — 20 subcaudals. Colour red on the body, with ill- defined cross-bars formed of yellowish black-edged scales ; a black blotch on the head, covering the vertex and temples, and surrounding the eyes; Fig. 62.-Rhynchelaps australis. another large blotch on the nape; snout and occiput yellow ; belly white. Total length, 290 millimetres ; tail 25. Habitat : Queensland. (3) B. semifasciatus—^coXe^ in 17 rows; 143—170 ventrals; 17 — 25 subcaudals. Colour yellow, with brown cross-bands; large brown blotches on the head and nape ; belly white. Total length, 300 millimetres ; tail 30. Habitat : West Australia. (4) B. f a sciolatus— Scales in 17 rows; 145 — 161 ventrals; 22—27 subcaudals. Colour red, with numerous blackish-brown cross-bands ; large blackish-brown blotches on the head and nape ; belly white. Total length, 335 millimetres ; tail 30. Habitat : West Australia. (p) Furina. (Figs. 63 and 64.) Maxillary bones extending forwards beyond the palatines, bear- ing a pair of moderately large grooved poison -fangs, and one or THE PBINCIPAL SPECIES OF POISONOUS SNAKES 99 two small teeth near their posterior extremities ; mandibular teeth subequal. Head small, not distinct from neck ; eyes very small, with round pupils ; nostril in a single nasal shield. Body cylin- drical ; scales smooth, in 15 rows. Tail very short, obtuse ; sub- caudals in 2 rows. (1) F. calonota. — Six su- pralabial shields ; 126 — 131 ventrals ; 29 — 30 subcaudals. Fig. 63. — Skull op Furina occipitalis. (After G. A. Bouleuger, ojp. cit.) Fig. 64. — Furina occipitalis. Colour yellow, with a black vertebral stripe ; a black bar across the end of the snout ; a large black blotch covering the vertex and the parietals ; belly white. Total length, 215 milli- metres ; tail 33. Habitat : West Australia. (2) F. himaculata. — Scales in 15 rows ; 181 — 200 ventrals ; 21 — 25 subcaudals. Colour yellow, with large black blotches on the snout, middle of head, and occiput ; belly v^^hite. Total length, 330 miUimetres ; tail 25. Habitat : West Australia. (3) F. occipitalis (fig. 64). — Scales in 15 rows; 180 — 234 ven- trals ; 14 — 25 subcaudals. Entire body ringed with black and white, annuli narrower on 100 VENOMS belly; head black, with a broad white band across the occiput, and another narrower and irregular one across the snout ; nose black. Total length, 590 millimetres ; tail 36. Habitat : Austraha. There are no poisonous snakes in New Zealand. In New Caledonia no terrestrial poisonous snakes are known, but Hydro- phiidcc abound on its shores, as on those of the majority of the islands of the Pacific. In Australia, especially in New South Wales and farther to the north, fatahties due to the bites of poisonous snakes are not rare. The most dangerous species are : Acanthopliis antarcticns (the Death Adder), Diemenia textilis (the Brown Snake), Pseudechis jporphyriacus (the Black Snake), and Notechis scutatns or Hoplo- cephalus curtics (the Tiger Snake). The health authorities of this country have accordingly taken the wise precaution of circulating very widely among the public coloured placards bearing illustrations of these four species, with a description of the essential anatomical details by which they may be recognised. Similar placards are exhibited in all the schools, and a generous distribution is made of instructions, printed on handkerchiefs, indicating the most effective method of treating poisonous bites. In Queensland, according to information furnished to me by Mr. C. W. De Vis, late Director of the Queensland Museum, Bris- bane, the number of deaths resulting from the bites of poisonous snakes has been only twenty-seven in ten years. E.~AMERICA. The fauna of the New World includes only a very small number of poisonous snakes belonging to the family Colubridjl. The Genus Elaps alone is represented there by twenty-eight species, scattered over Mexico, Central America, Bolivia, Ecuador, Peru, Colombia, and Brazil. THE FBINCIPAL SPECIES OF POISONOUS SNAKES 101 V1PEBID.E, on the other hand, are extremely nnmerons, and belong exclusively to the subfamily Crotalin^ ; there are no ViPERIN/E. I— COLUBRID/E. (a) Elaps. • (Fig. 65.) The characters of this genus are : Maxillary bones very short, extending beyond the palatines, and bearing a pair of large poison- FiG. 65.— Skull of Elaps marcgravii. (After G. A. Boulenger, op. cit.) fangs ; pterygoid teeth few or absent ; mandibular teeth all of equal length. No postfrontal bones ; pra3frontals meeting, or narrowly separated on the median line. Head small, not distinct 102 VENOMS from neck ; eyes small, with vertically elliptic or sub-elliptic pupils ; nostril between two nasal shields. Body cylindrical ; scales smooth, in 15 rows. Tail short; subcaudal scales in 2 rows, or partly single, partly in 2 rows. (1) E. siirinaj7iensis. — Seven supralabials, of which the fourth enters the eye ; frontal shield very narrow ; 167—182 ventrals. Colour red, with black annuli disposed in threes (the middle one broader), separated by narrow yellow interspaces; 7 or 8 sets of annuli on the body ; the red scales dotted with black ; head red above, with the shields black-edged, followed by a black cross-band behind the parietals. Total length, 740 milhmetres ; tail 95. Grows to 1,900 milli- metres. Habitat; Venezuela, Guianas, Northern Brazil, North-east Peru. (2) E. heterocJiiliis. — Six supralabials, second and third entering the eye ; snout narrow ; 209 ventrals. Colour red, with black annuli, as in E. marcgmvii. Total length, 553 millimetres ; tail 43. Habitat : Brazil. (3) E. euryxanthus (Sonoran Coral Snake). — Seven supralabials, third and fourth entering the eye ; internasals nearly as long as the praefrontals ; 215 — 241 ventrals ; 21 — 29 subcaudals. Colour red, with 11 black annuli edged with yellow ; head black. Total length, 400 millimetres ; tail 33. Habitat : Arizona, Colorado, North-western Mexico. It is found in Arizona up to an altitude of nearly 6,000 feet (1,800 metres). (4) E. gravenhorstii. — First lower labial in contact with its fellow; posterior nasal not reaching the prgeocular; 191 ventrals; 23 subcaudals. Colour : Seven sets of black annuli disposed in threes, median annulus the broadest ; head black, with a yellow transverse band behind the eyes. Total length, 550 millimetres ; tail 50. Habitat : Brazil. THE PRINCIPAL SPECIES OF POISONOUS SNAKES 103 (5) E. langadorffii. — Ventrals 204 — 225 ; subcaudals 37 — 54 ; 1 + 1 temporals. Colour dark brown, with 63 transverse series of cream-coloured spots, each occupying one scale ; belly yellow, with red cross-bands. Total length, 300 millimetres. Habitat: Upper Amazons. (6) E. buckletji. — 203 — 211 ventrals ; 39—43 subcaudals ; 1 + 2 temporals. Colour orange, with 48 — 60 black annuli edged with small yellow spots; head black; temples yellow. Total length, 505 millimetres ; tail 70. Habitat : Northern Brazil, Eastern Ecuador. (7) E. anomaliis.—'227 ventxaAs; 29 subcaudals ; 1 + 1 temi^orals. Colour : Body with 55 black annuli separated by narrow brownish-white bands; belly yellowish; anterior half of head black, posterior half yellow ; tail yellow or red, with 4 black rings. Total length, 280 miUimetres ; tail 23. Habitat : Colombia. (8) E. heterozo7ius.—'Sca}es in 15 rows; 210—219 ventrals; 16—23 subcaudals ; 1 + 1 temporals. Colour red or brown, with 17 to 23 black rings, mostly narrower than the interspaces ; a black band on the head across the eyes. Total length, 900 millimetres ; tail 40. Habitat: Eastern Ecuador, Eastern Peru, Bolivia. (9) E. elegans. —8c&les in 15 rows ; 189—221 ventrals ; 29—47 subcaudals ; 1 -f 1 temporals. Colour : Black annuli in sets of three, separated by reddish- brown interspaces ; 12—17 sets ; head black, with yellow blotches. Total length, 730 millimetres; tail 70. Habitat : Mexico and Guatemala. (10) E. annellatus.—^CQXes in 15 rows ; 200—211 ventrals ; 30 — 45 subcaudals ; 1 + 1 temporals. Colour black, with 41—49 narrow white rings on the body, 4 — 7 on the tail ; a white ring on the head. 104 VENOMS Total length, 490 millimetres ; tail 70. Habitat : Eastern Peru. (11) i/.fZecoraiiis.— Scales in 15 rows; 19(5— 213 ventrals: 29—37 subcaudals. Colour red, with 15—16 sets of black annuli disposed in threes ; head yellow, with end of snout black, and a black band across the eyes. Total length, 625 millimetres. Habitat : Brazil. (12) E.dumerilii. — Scales in 15 rows; 197— 204 ventrals ; 50—53 subcaudals. Colour : 8 — 9 sets of three black annuli on red and yellow ; head black, with a yellow band on the occiput. Total length, 410 millimetres; tail 65. Habitat : Colombia. (13) E. corallinus (The Coral Snake). — Scales in 15 rows; 179 — 231 ventrals; 30 — 47 subcaudals; 1 + 1 temporals. Colour : Body with black annuli, separated by red interspaces edged with yellow ; head bluish-black ; temples yellow ; a blue line from behind the eye to the lower jaw ; tail white. Total length, 790 millimetres ; tail 70. Habitat : Tropical South America and Lesser Antilles (St. Thomas, St. Vincent, Martinique). (14) E. hemprichii. — Scales in 15 rows ; 168 — 181 ventrals ; 22 — 29 subcaudals ; 1 + 1 temporals. Colour: Black, with red or yellow annuli, a broad annulus between the narrow ones ; occiput, upper lip, and temples yellow. Total length, 720 milliihetres ; tail 65. Habitat : Guianas, Colombia, Peru. (15) E. ^.sc//?i(:7u.— Scales in 15 rows ; 207 — 221 ventrals; 21—28 subcaudals. Colour : Body with black annuli broader than the interspaces, disposed in sets ; interspaces red and yellow ; snout and occiput black. Fig. GG.—Elcqjs fulvuis (The Harlequin Snake, or Coral Snake). (After L. Stejneger.) 106 VENOMS Total length, 430 millimetres ; tail 85. Habitat: Peru. (16) E. dissoleiicus— Scales in 15 rows; 200 ventrals ; 19 sub- caudals. Coloration as in foregoing species. Total length, 1,070 millimetres; tail 35. Habitat : Venezuela. (17) E. fulvius (Harlequin, or Coral Snake, fig. G6).— Scales in 15 rows ; 180—237 ventrals ; 30—59 subcaudals. Colour : Body with black, red, and yellow annuli ; tail with black and yellow annuli ; snout black. Total length, 990 millimetres ; tail 85. Habitat : Eastern North America, from Southern Virginia, the Ohio Eiver, and the Missouri to the Kio Grande, Mexico, Central America. (18) E. psyches. — Scales in 15 rows ; 188 — 214 ventrals ; 32 — 47 subcaudals. Colour: Body with alternate black and brown annuli, and 48 — 52 narrow yellow rings ; head black, blotched with yellow. Total length, 495 millimetres; tail 80. Habitat : Guianas. (19) E. s^ix'ii. — Scales in 15 rows ; 201 — 219 ventrals ; 22—29 subcaudals. Colour red, with 20 — 38 black rings disposed in threes ; a black occipital collar, followed by a wide red space. Total length, 1,400 millimetres ; tail 70. Habitat : Venezuela and Northern Brazil. (20) E. frontalis. — Scales in 15 rows ; 197 — 230 ventrals ; 15 — 26 subcaudals. Tail ending very obtusely. Colour : Body with black annuli disposed in threes, with red and yellow interspaces ; head black, spotted with yellow or red. Total length, 1,350 millimetres ; tail 70. Habitat : Southern Brazil, Uruguay, Paraguay, Argentina. (21) E. marcgravii. — Scales in 15 rows; 210 — 240 ventrals; 23 — 42 subcaudals. THE PEINCIPAL SPECIES OF POISONOUS SNAKES 107 Colour : Body with black annuli in 6 — 10 sets of three, separated by broad red interspaces, the middle annulus usually wider ; snout yellow, the end usually black ; back of head red. Total length, 1,120 millimetres ; tail 100. Habitat : Tropical South America. (22) E. lemniscatiL'i. — Scales in 15 rows ; 241 — 262 ventrals ; 30 — 39 subcaudals. Colour : Body with 11 — 14 sets of black annuli disposed in threes, separated by red interspaces ; head yellow ; end of snout and a band across the middle of the head black. Total length, 1,000 millimetres ; tail 80. Habitat : Guianas, Brazil. (23) E. filiforniis. — Scales in 15 rows ; 290 — 308 ventrals ; 35 — 45 subcaudals. Colour : Body with black annuli disposed in threes, with red interspaces ; head yellow ; end of snout black ; a black band across the eyes. Total length, 575 millimetres; tail 40. Habitat : Amazons, Colombia. (24) E. mipartitus. — Scales in 15 rows ; 210 — 278 ventrals ; 24- — 34 subcaudals. Colour black, with 40 — 68 narrow white annuli ; head black to between the eyes, elsewhere yellow. Total length, 610 millimetres ; tail 50. Habitat : Central America and Tropical South America. (25) E. fraseri. — Scales in 15 rows ; 303 ventrals ; 25 sub- caudals. Colour black, with 75 narrow ^yhitish rings with broken out- lines; head black in front, yellow behind. Total length, 780 njillimetres ; tail 40. Habitat : Ecuador. (26) E.??ze7i^aZis.— Scales in 15 rows; 255— 268 ventrals ; 30—31 subcaudals. Body black, with 58 — 70 narrow white annuli, which become 108 VENOMS Wider on the belly; snout black, occiput yellow; tail annulate, black and orange. Total length, 490 millimetres; tail 80. Habitat. — Colombia and Ecuador. (•27) E. a ncoralis. —ScB,]es in 15 rows; 258 ventrals; 31 sub- caudals. Colour : Body with 16 sets of black annuli disposed in threes, the middle one of each set a little wider; head light in front, spotted with black ; an anchor-shaped black mark on the occiput and nape. Total length, 780 millimetres ; tail 57. Habitat : Ecuador. (28) E. narduccii. — Scales in 15 rows ; 240—315 ventrals ; 15 — 33 subcaudals. Colour black, beneath with yellow or red cross-bands or trans- versely oval spots, sometimes extending as triangular blotches up the sides ; head with a yellow cross-band. Total length, 720 millimetres ; tail 50. Habitat : Eastern Ecuador, North-eastern Peru, Bolivia. The species of the genus Elaj:is, which are remarkable for the brightness and beauty of their colours, are generally found in forests. "The traveller," says Neuwied, "who ventures into the great Brazihan forests, where the ground is covered with leafy plants, is astonished to see shining through the verdure the black and red rings of the beautiful Coral Snake. Uncertainty as to whether the creature is dangerous alone prevents him from seizing it. The body of the snake is not lithe .enough to enable it to climb trees. Its food consists of small animals." Dr. Lacerda relates that the Austrian naturalist Wertheimer, when in the Brazilian settlement of Philadelphia, was bitten by a Coral Snake in the back of the hand. The usual symptoms of poisoning manifested themselves immediately, and the unfortunate man died twelve hours later. Nevertheless, the small size and THE PRINCIPAL SPECIES OF POISONOUS SNAKES 109 slenderness of the fangs, the narrowness, of their canals, and the considerable distance between the fangs and the anterior opening of the mouth, must necessarily render the bites of these snakes less serious and of rarer occurrence. II.— VIPEEID.E.— CEOTALIN.E. The Solenoglyplia are infinitely more for- midable in the two divisions of the New World. They are re- presented by a large number of species, some of which are feared in consequence of their size and ferocity, even more than on account of the deadliness of their venom (fig. 67). The American Cbo- TALIN^ are divided into two groups : — The first of these comprises snakes not provided with the cau- dal appendage, which is characteristic of the Rattle-Snakes. It con- sists of two genera : — (a) Ancistrodon. Fig. 67. — Head and Skull of Crotalus horridus. (b) Lachesis. The second group includes only those snakes the tails of which are terminated by the scaly appendage known as the " rattle." 110 VENOMS The Water Viper lives for These are likewise divided into two genera : — (c) Sistrurus. (d) Grotalus. (a) Ancistrodon. Usually with 9 shields on the head, or internasals and prsefron- tals broken up into scales. Body cylindrical ; scales smooth or keeled, with apical pits. Tail moderate or short ; subcaudals single or in 2 rows. (1) A . piscivorus (Water Viper, or Cotton-mouth ; fig. 68). — Snout rounded, soft above. Scales on the body strongly keeled, in 25 (rarely 27) rows; 130—147 ven- trals ; 33 — 51 subcaudals, all single or the posterior divided. Colour pale reddish-brown to dark brown above, with more or less distinct dark brown cross- bands, or with alternating C-shaped dark markings each en- closing a central spot. Belly dull yellow spotted with black, or al- most black. Total length ,1,170 millimetres ; tail 200. Habitat : Eastern North America, from North Carolina and Indiana to Florida and Texas, the most part in the vicinity of THE PRINCIPAL SPECIES OF POISONOUS SNAKES 111 rivers, and feeds upon fish, but also devours small warm-blooded animals. The Creoles call it the Congo Snake. It is fairly common in the environs of New Orleans. In summer time it conceals itself in the branches of trees at the edge of the water. It frequents inundated rice-fields, and is a terror to the blacks. It attacks readily, and opens its jaws some seconds before it bites. (2) A. hilineatiLs. — Snout obtusely pointed. Scales more or less strongly keeled, in 23 (rarely 2-5) rows ; 135 — 141 ventrals ; 52 — 64 subcaudals, anterior single, posterior divided. Colour dull yellow or reddish-brown, with more or less distinct darker cross-bands, or alternating transverse blotches, with yellow edges ; a vertical yellow line on the rostral shield, and a fine yellow line round the snout ; belly brownish or blackish, with Avhite spots. Total length, 1,100 milhmetres ; tail 200. Habitat: Mexico, Guatemala, Honduras. (3) A. contortrix (The Copper-head). — Snout rounded or trun- cate. Scales strongly keeled, in 23 (rarely 25) rows ; 145 — 155 ventrals ; 31 — 52 subcaudals, anterior single, posterior divided. Colour dull yellow or reddish-brown, with dark brown or brick-red cross-bars ; these bars are sometimes interrupted on the vertebral line, and form alternating triangles ; belly yellow or reddish, more or less spotted with grey or brown. Total length, 990 millimetres ; tail 110. Habitat: North America, from Massachusetts and Kansas to Northern Florida and Texas. This snake is often more dreaded than a Eattle-Snake. (b) Lachesis. In Lachesis the caudal rattle is represented by a series of 10 or 12 rows of spiny scales, which are slightly hooked at the tips. The head is covered with small shields or smooth or keeled scales, wither without apical pits. The maxillary is much reduced; the transverse or pterygoid bone, on the contrary, is greatly developed. 112 VENOMS The name is derived from one of the Parcae, daughters of Night, who placed the thread on the spindle, and upon whom depended the fate of men. In addition to the 19 Asiatic species, of which we have already given descriptions, the genus Lachesis includes 21 American species. (1) L. mutus (Bushmaster, or Surucucu).— Two or three scales separating the internasals in front; 10 to 15 scales on a line be- tween the supraoculars ; 9 or 10 supralabials. Scales tubercularly keeled, feebly imbricate, in 35 or 37 rows; 200—230 ventrals ; 82 — 50 subcaudals. Fig. G9. — Lachesis lanceolatus {Fcr-dc-lancc of Martinique). (After Stejneger.) Colour yellow or pinkish on the back, with a series of large rhomboidal brown or black spots enclosing smaller light spots ; a black streak from the eye to the angle of the mouth. Total length, 1,995 millimetres ; tail 170. Habitat : Central and Tropical South America. (2) L. lanceolatus (known as the Fer-de-lance in Martinique, and Jararacussu in Brazil; fig. 69). — Snout obtuse, slightly turned up ; upper head-scales small, imbricate, more or less strongly keeled, in 5 — 10 longitudinal series between the supraoculars, which are large ; 7 or 8 supralabials. Scales in 23 — 33 rows, THE PBINCIPAL SPECIES OF POISONOUS SNAKES sharply keeled; 180—240 ventrals; 46—70 subcaudals, all or the greater part in two rows. Coloration very variable, grey, brown, yellow, oHve, or reddish ; uniform or with more or less distinct dark spots, or cross-bands, or with dark triangles on the sides enclosing pale rhombs ; a dark streak from the eye to the angle of the mouth ; belly yellowish, uniform, or spotted with brown. Total length, 1,600 milhmetres ; tail 190. Habitat: Tropical America; Mexico, Martinique, St. Lucia, Bequia Island near St. Vincent, Venezuela, Guianas, Eio de Janeiro. This snake does not exist m Guadeloupe. " In the islands in which it is found," says Dr. Eufz de Lavison, " its presence makes itself felt even- where man has built his dwelhng and cultivates the soil. Because' of it no one can carelessly lie down to rest in the shade of a tree ; no one can walk in the woods or enter un- concernedly into the pleasures of the chase." It is especially abundant in coffee and sugar plantations, and is met with from the sea-level up to the summits of the highest mountains in Martinique and St. Lucia. It not infrequently makes its way into human habitations, and is not uncommon in gardens, even entering those of the town of Fort-de-France. It does not seek its prey by day, but remains on the alert, always ready to bite. With open mouth, and fangs projecting for- wards, it strikes with the rapidity of lightning. It swims in the rivers and moves over the ground with great speed. Oviposition takes place in July, and the young are hatched forthwith, the usual number being from about 50 — 60. It feeds upon lizards and rats, but also destroys a certain number of fowls and turkeys. All the large animals are afraid of it. Its bite is extremely dangerous, and causes about a hundred deaths in Martinique every year. In striking at its prey or at a man, the Fer- de-lance throws back its head and opens its jaws widely, with the fangs directed forwards. It drives in its poison-teeth as with the blow of a 8 114 VENOMS hammer, and quickly draws back again. When very excited, it resumes its position and strikes afresh. It never becomes tame, but is capable of living a fairly long time in captivity. I have kept a number of specimens of it for more than two years, caged in my laboratory. (3) L. atrox (Labaria). — Closely resembling L. lanceolatus, but bulkier ; the enormous head is armed with powerful fangs, which are often more than a centimetre in length ; 7 supralabial shields ; scales in 25 — 29 rows, strongly keeled ; 161 — 21f3 ventrals ; 47 — 73 pairs of subcaudals. Colour brown, with dark cross-bands or triangular blotches, with the apices adjacent on the vertebral line ; a dark streak from the eye to the angle of the mouth ; belly yellowish-white, speckled with brown, or brown spotted with yellowish-white. Total length, 1,110 millimetres; tail 180. Habitat: from Central America to Peru and Northern Brazil. (4) L. pulcher. — Two postocular shields and a subocular, separated from the labials by one series of scales : 7 supralabials ; scales in 21 or 23 rows, strongly and tubercularly keeled : 156 — 172 ventrals ; 58 — 64 pairs of subcaudals. Colour olive-grey, with brown, light-edged cross-bands, which are continuous or broken on the vertebral line ; a light streak from the eye to the angle of the mouth ; belly covered with minute confluent brown markings, with darker and lighter spots on the sides. Total length, 685 millimetres; tail 115. Habitat : Andes of Ecuador. (5) L.microphthahnus. — Snout short, rounded ; eyes very small ; 7 supralabials, of which the third and the sixth or seventh are the largest ; scales in 23 rows, dorsals tubercularly keeled ; 159— 161 ventrals ; 52 — 55 subcaudal pairs. Colour yellowish-brown or pale olive on the back, with dark brown triangles on the sides; posteriorly, the united triangles form cross-bands ; a yellowish band from the eye to the side of the neck ; belly dark brown with yellowish spots. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 115 Total length, 630 millimetres ; tail 100. Habitat : Peru, Ecuador. (6) L. pictus. — Snout obliquely truncate ; two series of scales between the eye and the labials; scales in 21 — 23 rows, strongly keeled; 157 — 172 ventrals ; 40 — 74 pairs of subcaudals. Colour pale brown, with a dorsal series of large black-edged brown spots, which may form a vertebral zigzag band ; a black streak behind the eye, and a vertical bar below the eye ; belly yellowish, spotted with brown. Total length, 310 millimetres ; tail 43. Habitat: Peru. (7) L. alternat'us. — Head narrow, elongate; 8 — 9 supralabials ; scales in 29 — 35 rows, very strongly keeled ; 167 — 181 ventrals ; 34 — 51 pairs of subcaudals. Colour brown, very elegantly marked with opposite or alternat- ing pairs of large C-shaped markings, which are dark brown, edged with black and yellow, and separated by narrow interspaces of the ground colour; head dark brown above, with a ^-shaped light marking, the transverse bar between the eyes ; belly whitish, spotted with brown or black. Total length, 1,190 milhmetres ; tail 110. Habitat : Southern Brazil, Paraguay, Uruguay, Argentina. (8) L. neuwieclii (known as the Urtitu in Brazil ; fig. 70). — Snout obtusely pointed ; supraocular large, separated from its fellow by 6—9 longitudinal series of scales ; 8 or 9 supralabials ; scales very strongly keeled, in 21—27 rows; 168—182 ventrals; 41 — 53 subcaudals. Colour yellowish or pale brown, with dark brown black-edged spots ; the spots on the back form a single series or a double alternating series ; a dark spot on the snout ; a pair of dark bands from the vertex to the nape, and another from the eye to the angle of the mouth ; belly yellowish, more or less powdered with brown. Total length, 770 millimetres ; tail 120. Habitat : Brazil, Paraguay, Argentina. 116 VENOMS Fig. lO.—Lachesis ncuwiedii (known as the Unilii in Brazil). (After Lacerda.) THE PRINCIPAL SPECIES OF POISONOUS SNAKES 117 (9) L. ainmodytoides. — Snout turned up, in the shape of a wart ; two series of scales between the eye and the labials ; scales in 23 or 25 rows, wery strongly keeled ; 149—160 ventrals; 30 — 38 pairs of subcaudals. Colour pale brown, with large brown black-edged spots or cross-bands, which may alternate and form a zigzag band ; a dark streak behind the eye ; belly yellowish, spotted with brown. Total length, 460 millimetres ; tail 55. Habitat : North-eastern Patagonia and Argentina. (10) L. xantliogrammus. — Head elongate, snout short ; scales in 27 rows, feebly keeled ; 196 ventrals ; 54 subcaudals. -Colour very dark ohve, with a yellow zigzag line on each side from the head to the base of the tail ; the angular parts enclose rhombic spaces and lateral triangles ; top of head black, with a pair of undulating yellow bands from the nape to the vertex ; a bright golden band round the snout ; labials bright yellow ; ventral shields black, paler in the middle, with yellow triangular spots at their extremities. Total length, 1,530 mihimetres ; tail 190. Habitat : Eastern Ecuador, Andes of Colombia. (11) L. castelnaudi. — Head narrow and elongate ; scales on the head smooth or feebly keeled, small ; body-scales strongly keeled, in 25 or 27 rows ; 230—253 ventrals ; 72—83 subcaudals, all or majority in a single row. Colour greyish or brown, with dark or light-edged spots or cross-bands; head with dark spots, one of which occupies the middle of the snout ; a dark band from the eye to the angle of the mouth ; belly brown or blackish, spotted with yellow. Total length, 1,220 millimetres ; tail 180. Habitat: Brazil, Ecuador, Eastern Peru. (12) L. 7vuvimifer. — Snout broad, rounded ; 10 or 11 supralabials ; scales in 23—27 rows, strongly keeled; 121— 134 ventrals ; 26—36 subcaudals, all or the majority single. Colour pale brown, with a dorsal series of rhomboidal spots. 118 VENOMS which may form a zigzag band ; belly whitish, uniform or spotted with dark brown. Total length, 800 millimetres ; tail 90. Habitat : Mexico and Central America. (13) L. godmani. — Snout broad, rounded ; \) or 10 supralabials ; scales in '21 rows, strongly keeled ; 135 — 142 ventrals ; 22 — 34 subcaudals in a single row. Colour brown, with or without a dorsal series of large darker spots; belly yellowish, more or less spotted with grey or blackish. Total length, 610 millimetres ; tail 60. Habitat : Guatemala. (14) L. lansbergii. — Snout pointed, turned up at the end, as in Vipera aspis ; scales in 25 — 27 rows, strongly keeled; 152 — 159 ventrals; 29 — 35 subcaudals in a single row. Colour yellowish-brown, pale brown, or grey, with a dorsal series of large rhomboidal or squarish spots, usually divided by a narrow yellow or orange vertebral line ; cheeks blackish ; belly powdered with brown, with or without whitish spots. Total length, 575 millimetres ; tail 70. Habitat : from Southern Mexico to Colombia, Venezuela, and Brazil. (15) L. brachystoma. — Similar to the foregoing species ; scales in 23 (rarely 25) rows ; 132 — 150 ventrals ; 27 — 88 subcaudals. Total length, 500 millimetres ; tail 50. Habitat : Southern Mexico and Central America. (16) L. bilineatus. — Snout rounded; 7 or 8 supralabials; scales in 27 — 35 rows, strongly keeled ; 198 — 218 ventrals ; 59 — 71 subcaudals, all or majority in two rows. Tail prehensile. Colour green, uniform or spotted with black ; a lateral yellow streak; belly white; end of tail reddish. Total length, 840 millimetres ; tail 125. Habitat : Brazil, Bolivia, Peru, Ecuador. (17) L. tmdulatus—iiuout short, rounded ; 11 supralabials ; scales in 21 rows, the dorsals strongly or very strongly keeled ; 149 — 171 ventrals; 41 — 49 pairs of subcaudals. Tail prehensile. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 119 Colour olive or brown, sometimes speckled with black, with a dorsal series of rhomboidal dark spots or an undulous or zigzag band ; belly yellowish or brownish, powdered with blackish. Total length, 570 millimetres ; tail 75. Habitat : Mexico. (18) L. lateralis. — Snout rounded ; 9 supralabials ; scales in 21 or 23 rows, rather strongly keeled ; 171 ventrals ; 59 subcaudals, in ■a single row. Tail prehensile. Colour green, with a yellow line on each side of the body. Total length, 485 millimetres ; tail 75. Habitat : Costa Rica. (19) L. bicolor. — Very similar to the foregoing ; scales in 21 rows ; 164 — 167 ventrals ; 62 — 67 subcaudals, in a single row. Colour uniform green, yellowish on the belly. Total length, 375 millimetres ; tail 60. Habitat : Guatemala. (20) L. schlegelii. — Snout rounded ; 8 or 9 supralabials ; scales in 19 — 25 rows, more or less strongly keeled ; 138 — 162 ventrals ; 47 — 62 subcaudals, in a single row. Tail prehensile. Coloration very variable, green or olive, spotted with black, or with pinkish, reddish, or purplish black-edged spots or cross-bars ; behy yellow, spotted with green, or variegated ; end of tail generally red. Total length, 600 millimetres ; tail 115. Habitat : Central America, Colombia, Ecuador. (21) L. nigroviridis. — Snout short, rounded ; 9 — 11 supralabials ; 19 rows of scales, rather feebly keeled ; 134 — 146 ventrals ; 49 — 54 subcaudals, in a single row. Tail prehensile. Colour green or olive, spotted with black ; head with a black streak on each side ; belly yellowish. Total length, 535 millimetres; tail 90. Habitat : Costa Rica. (22) L. aurifer. — Snout short and broad ; 9 or 10 supralabials ; scales in 19 rows, rather strongly keeled ; 154 — 158 ventrals ; 53 — 61 subcaudals, single. Tail prehensile. 120 VENOMS Colour green, spotted with yellow ; a black streak on the temple ; belly greenish-yellow. Total length, 825 millimetres ; tail 145. Habitat : Guatemala. (c) Sistrurus. Head very distinct from neck, covered above with nine large symmetrical shields ; eyes rather small, with vertical pupils. Body cylindrical ; scales keeled, with apical pits ; tail short, ending in a segmented horny apparatus (rattle), producing a special sound; subcaudals all or the majority in a single row. (1) S. miliarius (Ground Kattle-Snake). — 9 — 11 supralabials ; scales in 21 or 23 rows, strongly keeled ; 127—139 ventrals ; 27—36 subcaudals ; rattle short, consisting at the most of 10 segments. Colour greyish, yellowish, or brown, the vertebral line often orange ; two undulating dark stripes from between the eyes to the occiput, the enclosed space usually orange ; belly whitish, spotted with dark brown or black. Total length, 520 millimetres ; tail 70. Habitat : South-eastern North America, from North Carolina to Texas. (2) S. catenatus (Prairie Rattle-Snake, or Massasanga, fig. 71). — Two or three series of scales between the eye and the labials ; 11 — 14 supralabials ; scales in 23 or 25 rows ; 136 — 153 ventrals ; 20 — 31 subcaudals. Colour the same as in S. miliarius; a dark spot on the parietal shields. Total length, 680 millimetres; tail 80. Habitat: Great Lakes district; United States east of the Rocky Mountains and west of the Mississippi ; Northern Mexico. (3) S. ravus. — 11 or 12 supralabials ; scales in 21 or 23 rows ; 147 ventrals ; 26 subcaudals. Colour yellowish-brown, with a dorsal series of dark brown THE PBINCIPAL SrECIES OF POISONOUS SNAKES Fig. ll.—Sistruriis calcnatus (Prairie Rattle- Snake, or Massasanga). {After Holbrook and Stejncger.) 122 VENOMS spots, longer than broad, and a series of transverse dark bars on each side ; belly yellowish, spotted with blackish-brown. Total length, 200 millimetres ; tail 22. Habitat : Veva, Cvnz, Mexico. (d) Crotalus (Rattle- Snakes). These snakes differ from all others in that the end of the tail bears a series of large conical scales, forming rattles, each fitting into the next and movable in such a manner that when the reptile causes them to move they produce a strident sound (fig. 72). The length of these animals often exceeds 2,000 mil- limetres. The head is flat, very large and expanded pos- teriorly, and ter- minated in front by a short, truncate snout ; it is covered above with scales or small shields. Rattle - Snakes are armed with enor- mous fangs enclos- ing a complete canal, which extends throughout almost their entire length. The poison - glands are of the size of a large almond. The number of segments in the rattle is variable, but rarely exceeds 18 or 20. At the time of the shedding of the skin these B b d h 0 f g Fig. 72. — A, Horny appendage (rattle) of Crotalus horridus (three-quarters natural size. After Garman). B, longitudinal section of the same. C, separated segments of the appendage : a, terminal point ; /(, basal segment (after Czermak). THE PBINCIPAL SPECIES OF POISONOUS SNAKES 128 Pig. 13. —Crotahis terrificus (Dog-faced Rattle-Snake, Cascavella in Brazil). (After Stejneger.) 124 VENOMS segments fall off and are at once replaced Contrary to the belief which was long entertained, tlieir number bears no relation to the age of the snake. Rattle-Snakes are met with especially in stony and arid localities, or among brushwood near water. They hardly ever bite except when surprised or attacked. (1) C. terrificus (Dog-faced Rattle-Snake, Cascavella in Brazil ; fig. 73).— Snout very short; three or four series of scales between the eye and the supralabial shields; body-scales in 23—31 rows, dorsals very strongly keeled; 160—199 ventral s ; 18—30 sub- caudals. Colour brown, with a series of darker, light-edged rhombs, often lighter in the centre; a dark streak from the eye to the angle of the mouth ; belly yellowish -white, uniform or spotted with brown ; tail generally brown or blackish. Total length, 1,320 millimetres ; tail 130. Habitat : Arizona, New Mexico, and Texas to Southern Brazil, and Northern Argentina. (2) C. scutulatus {Texas B,a.tt\e-^nake ; fig. 74).— 13 — 16 supra- labials; scales in 25 or 27 rows; dorsals striated and strongly keeled ; 167—170 ventrals ; 18—20 subcaudals. Colour yellowish or greyish-brown, with a series of large dark brown light-edged rhomboidal spots ; an oblique dark streak below the eye ; belly uniform yellowish-white. Total length, 760 millimetres ; tail 65. Habitat: Arizona, New Mexico, Texas, North Mexico. (3) C. confluentus (Pacific or Mottled Rattle-Snake; fig. 75). — Upper head-scales small, striated ; 13 — 18 supralabials ; body scales in 25 — 29 rows, striated and strongly keeled ; 168 — 197 ventrals ; 17 — 34 subcaudals. Colour yellowish, greyish, or pale brown, with a dorsal series of large brown or red spots, usually rhomboidal or transversely elliptic in shape ; a light streak or triangular marking across the supraocular shields ; belly yellowish, uniform or spotted with brown. THE PBINCIPAL SPECIES OF POISONOUS SNAKES 125 Total length, 1,520 millimetres ; tail 140. Habitat : Western North America, from British Columbia to South California, eastwards to Assiniboia, Dakota, Nebraska, Kansas, and Western and Southern Texas ; Northern Mexico. According to Holbrook, this reptile feeds upon young rabbits, squirrels, rats and other small mammals. It lays its eggs in August, and the young are hatched at once, and are capable of seeking their own food. In captivity as well as under natural conditions the Mottled Eattle-Snake is an excessively irritable species. " The noise of the wind," says Brehm, "or even the distant view of a man or animal, are sufficient to irritate it. It then coils itself up in a spiral, and places its head and tail in the centre of the disc thus formed, in a state of absolute immobihty. After a short interval the creature raises its head to a height of about 8 to 12 inches above the ground, curves its neck in the shape of an S, and elevates its tail into a vertical position and shakes it vigorously, whereupon the strident noise caused by the rattle is heard. So rapid are the movements communicated by the Crotalus to its tail that they can scarcely be distinguished. So long as the Crotalus believes itself menaced it remains in the position that we have just described, and continues to sound its rattle. If one withdraws from the irritated snake, the sound gradually lessens and ceases, to begin again more vigorously when the reptile is once more approached." The bite of these snakes is exceedingly dangerous. Pigs wage an inveterate war against them and devour them. At the Pasteur Institute at Lille, I have kept several of these reptiles in captivity for eighteen months and longer. They invariably refused their food, and I always had to resort to artificial feeding. They are easily capable of withstanding a prolonged fast. (4) G. clurissus (Common Eattle-Snake).— 7 or 8 longitudinal Fig. 74. , — CrotaluH scntulatus (Texas Rattle-Snake). (After Baird and Stejneger.) THE PBINCIPAL SPECIES OF POISONOUS SNAKES 127 series of scales between the supraoculai-s, 3 or 4 series of scales between the eye and the labials ; 13 — 16 supualabials ; scales in 25 — 29 rows, dorsals strongly keeled ; ventrals 169 — 181 ; 24 — 32 subcaudals. Colour pale greyish or brownish, with a dorsal series of large blackish rhomboidal spots ; a yellowish cross-line between the eyes; snout blackish; end of tail usually black; belly yellowish, more or less spotted with brown or black. Total length may be as much as 8 feet (2,400 millimetres) . Habitat : South-eastern United States, from North Carolina to Florida and the mouths of the Mississippi. (5) G. horridus. — Supraoculars considerably narrower than the space between them, which is covered by 3 — 8 longitudinal series of small scales ; 12 — 16 supralabials ; body scales in 23 — 29 rows, dorsals very strongly keeled ; 165 — 178 ventrals ; 19 — 29 sub- caudals. Colour greyish-brown, usually with a rusty vertebral stripe, and V- or M -shaped blackish cross-bands ; head uniform above, with a dark band from the eye to the angle of the mouth ; usually a pair of roundish or triangular dark spots on the nape ; belly yellowish, uniform or spotted with blackish ; end of tail blackish. Total length, 1,340 millimetres ; tail 135. Habitat : United States, from Massachusetts and Iowa to Northern Florida and Texas. (6) C. tigris. — 13 — 15 supralabials ; scales in 23 or 25 rows, dorsals strongly keeled ; 166 — 181 ventrals ; 26 — 46 subcaudals. Colour yellowish or pale brown, with a dorsal series of brown spots and cross-bands posteriorly ; sides with smaller dark spots ; belly yellowish, spotted with brown. Total length, 380 millimetres ; tail 50. Habitat : Southern California, Lower California, Nevada, Colorado, Arizona, and Northern Mexico. (7) C. mitchelli. — 14 — 16 supralabials ; scales in 25 rows, striated, dorsals strongly keeled ; 178 — 198 ventrals ; 24 — 26 subcaudals. Fig. 75. — Crotalus confltientiis (Pacific or Mottled Rafctle-Snake). (After Baird and Stejneger.) THE PRINCIPAL SPECIES OF POISONOUS SNAKES 129 Colour greyish-yellow to salmon-red, finely punctulated with brown, with a dorsal series of transverse darker spots ; belly yellowish. Total length, 1,020 millimetres ; tail 90. Habitat: Desert regions of Southern California, Lower Cali- fornia, and Arizona. (8) G. triseriatus. — 9 — 13 supralabials ; scales in 21 — 25 rows, dorsals strongly keeled ; 142—184 ventrals ; 22—30 subcaudals. Colour olive or brown, with a vertebral series of rather small dark brown spots edged with black and white; belly yellowish, spotted with dark brown, or dark grey-brown powdered with whitish. Total length, 530 millimetres ; tail 55. Habitat : Mexico. (9) C. polystictus. — Closely allied to the foregoing, but 4 inter - nasals, 14 or- 15 supralabials, and scales in 27 — 30 rows ; 123 151 ventrals ; 18 — 23 subcaudals. Colour yellowish-brown, beautifully marked with 6 or 7 longi- tudinal series of alternating, elongate, dark brown, black- and white- edged spots, separated by narrow interspaces of the ground-colour ; a pair of diverging dark bands on the top of the head, separated by a narrow "pinkish- white streak; belly pinkish or yellowish, spotted with dark brown. Total length, 600 millimetres ; tail 60. Habitat : Tableland of Mexico. (10) G. lepidus. — 12 supralabials ; scales in 21 or 23 rows, dorsals strongly keeled ; 153—169 ventrals ; 24—31 subcaudals. Colour brown or greenish-grey, with dark brown or jet-black light-edged cross-bauds, narrowing on the sides; two dark spots, or a V- or heart-shaped black marking on the nape ; belly dirty white, spotted with brown. Total length, 350 millimetres ; tail 60. Habitat : Western Texas, New Mexico, Arizona, North Mexico. (11) C. cerastes (Horned Eattle-Snake ; fig. 76).— Supraocular 9 Fig. 76. — Croiahis cerastes (Horued Kattle-Snake.) (After Baird and Stejneger.) THE PBINCIPAL SPECIES OF POISONOUS SNAKES 131 transformed into a raised horn-like process ; 11—13 supralabials • scales in 21 or 23 rows; dorsals feebly keeled, each scale along the middle of the back with a central tubercular swelling; 146 ventrals; 17 subcaudals. Colour yellowish, with a dorsal series of rather indistinct brown blotches ; a narrow brown streak from the eye to the angle of the mouth. Total length, 250 millimetres ; tail 20. Habitat: Desert regions of Southern California, Nevada, Arizona, and Utah. F.—HYDBOPHIINM (SEA-SNAKES). The Sea-Snakes, which are found in great numbers on the shores of the Indian Ocean, are common throughout the whole of the tropical zone of the China Sea and the Pacific. They are met with from the Persian Gulf to the west coast of Equatorial America, but are entirely absent from the east coast of the same continent and the west and east coasts of Africa. They often travel in companies. All are poisonous, and very savage. They never come to land, and move with difficulty if taken out of the water, although they are excellent swimmers. It is impossible to keep them in captivity in aquariums, and they die m two or three days. Their food consists of fishes and Crustacea. Their tail is prehensile, and they make use of it as an anchor to attach themselves to coral reefs when they wish to rest. They generally float on the surface of the waves,' but can dive to great depths, thanks to the extreme dilatability of their lungs, which enables them to store up large reserves of air. They are viviparous. In these snakes, the head, which is always very small is scarcely distinct from the body. It is often covered with nine large shields. The body is laterally compressed, and the tail, which serves as a fin, is similarly flattened. The nostrils open 132 VENOMS on the upper surface of the snout, between the nasal shields. The eyes are always very small. The number of species at present known is considerable ; they are divided into ten genera. We shall confine ourselves here to mentioning the principal diagnostic characters of these genera, and to describing the most common species. Fig. 77. — Skull of Hydrus platurus. (After G. A. Boulenger, op. cit.) (1) Hydrus. (Fig. 77.) Maxillaries longer than the ectopterygoids, not extending forwards as far as the palatines; poison-fangs grooved, rather short, followed, after an interspace, by 7 or 8 solid, backwardly THE PRINCIPAL SPECIES OF POISONOUS SNAKES curved teeth. Snout long, bearing the nostrils on its upper surface ; head-shields large, nasals in contact with each other. Body rather short; scales hexagonal or squarish, juxtaposed ; no distinct ventral scales. The principal species of this genus is H. platitrus (syn. Pelamis hicolor, fig. 78). Coloration black or brown and yellow, with very variable markings. Total length, 700 millimetres ; tail 80. Habitat : Indian Ocean, Tropical and Sub-tropical Pacific. Fig. 78. — Hijdrus platurus (syn. Pelamis bicolor). (After Krefft.) (2) Thalassophis. Poison-fangs followed by 5 small teeth. Snout short ; nostrils superior, horizontal, between two nasal shields and an inter-nasal ; frontal and parietal shields large ; prasocular present. Body rather elongate ; scales hexagonal, juxtaposed ; no distinct ventral scales. T. anomalus. — Body with dark annuli, wider on the back. Total length, 810 millimetres ; tail 84. Habitat : Java. (3) Acalyptophis. Maxillaries longer than the ectopterygoids ; frontal and parietal shields broken up into scales. Body rather elongate ; scales sub- imbricate ; no distinct ventrals. A. peronii. — Greyish or pale olive, with dark cross-bands ; belly whitish. Total length, 890 millimetres ; tail 115. Habitat : Western Tropical Pacific. 134 VENOMS (4) Hydrelaps. Snout short ; 6 teeth behind the poison-fangs ; nostril in a single nasal shield ; head-shields large. Body feebly compressed ; scales imbricate ; ventral scales small, but well developed. H. darwiniensis. — Body with yellowish- white and blackish cannuh, the black rings narrower on the belly ; head dark olive spotted with black. Total length, 435 millimetres ; tail 43. Habitat : North Australia. (5) Hydrophis. (Fig. 79.) Poison-fangs large, followed by a series of 7 — 18 solid teeth. Head small ; nostrils on the upper surface of the snout, pierced in a single nasal shield ; head - shields large ; prseocular present. Body long, often very slender anteriorly ; scales on the anterior part of the body imbricate, rectangular, keeled or tubercular ; ventrals more or less distinct, very small. A considerable number of (at least 22) species of Hydkophis are known. Those most frequently met with are the following : — Fig. 79. — Hydrophis coronatus. (After Sir Joseph Fayrer.) THE PRINCIPAL SPECIES OF POISONOUS SNAKES 135 H. spiralis. — Olive above, yellowish beneath, with black rings ; head black above, with a horse-shoe-shaped yellow mark, the convexity of which rests on the praefrontal shields ; end of tail black. Total length, 400 millimetres. Grows to 1,800 millimetres. Habitat: Coasts of India, and the Malay Archipelago. H. ccerulescens. — Grey above, with black cross-bands, which form complete rings, or are interrupted on the belly ; head miiform black. Total length, 665 millimetres; tail 75. Habitat: Bombay Coast, Bay of Bengal, Straits of Malacca. H. nigrocinctus. — Pale olive on the back, yellowish on the belly, with black annuli, which are broader on the back. Total length, 1,000 millimetres ; tail 100. Habitat: Bay of Bengal and Straits of Malacca. H. elegans (fig. 80). — Yellowish-white, back with transverse rhomboidal black spots, separated by a series of small black spots ; belly with black spots or cross- bars ; head blackish, with a more or less distinct light crescentic marking across the snout, from above the eyes. Total length, 710 millimetres ; tail 60. Habitat : North coast of Australia. H. gracilis. — Bluish-black or greyish, olive above in the adult, with more or less distinct lighter cross-bands anteriorly. Young sometimes with rhombic black cross-bands extending to the belly, or sub-interrupted on the sides. Total length, 1,020 milhmetres ; tail 90. Habitat : Coasts of Persia, India, and Ceylon ; Malay Archipelago. H. cantoris. — Body dark olive or blackish anteriorly, with yellowish cross-bands above; posterior part of body ohve above, yellowish on the sides ; tail with olive vertical bars ; a blackish streak along the belly. Pig. 80. — Hydropliis elegans. (After KreSfc.) 136 VENOMS Total length, 1,100 millimetres ; tail 90. Habitat : Bay of Bengal. H. fasciat7is.—B.ea.d and neck black, the latter with yellowish cross-bands; body pale, with black annuli, which are broader on the back. Total length, 1,000 millimetres ; tail 85. Habitat: From the coasts of India to China and New Guinea. H. obscurus (syn. H. stricticollis).— Olive or dark green above, with yellowish cross-bars, which form complete rings round the slender anterior part of the body ; a yellow spot on the snout, and a yellow streak on each side of the upper surface of the head. Total length, 970 millimetres; tail 105. Habitat : Bay of Bengal, Malay Archipelago. H. leptodira. — Black, with yellow cross-bars on the neck, and complete annuli on the body, the bars and annuh numbering 77. Total length, 525 millimetres ; tail 40. Habitat : Mouths of the Ganges. (6) Distira. (Fig. 81.) Poison-fangs large, followed by 4—10 grooved teeth. Head larger than in Hydrophis ; body more or less elongate ; scales on the anterior part of the body imbricate ; ventrals more or less distinct, and always very small. The species of this genus, 18 in number according to the British Museum Catalogue, are found in the Indian and Pacific Oceans, from the Persian Gulf to Japan and New Caledonia. The most important are : — D. ornata. — Uniform blackish-olive on the back, whitish on the belly. Total length, 1,200 millimetres ; tail 130. Habitat : From the Mouth of Persian Gulf, and the coasts of India and Ceylon to New Guinea, and North Australia. THE PRINCIPAL SPECIES OF POISONOUS SNAKES 137 D. subcincta. — Trunk with 41 broad dark cross-bands, about as broad as the interspaces, not extending downwards to the middle of the side ; a series of small roundish, blackish spots along the lower part of the sides. Total length, 1,070 millimetres ; tail 100. Habitat : Indian Ocean. Fig. 81.— Skull of Distira. (After G. A. Boulenger, op. cit.) D. cyanocincta. — Greenish-olive above, with dark olive or black cross-bars or annuli, broader on the back, and sometimes joined by a black band along the belly, or yellowish, with a black vertebral stripe and a few bars on the neck. Total length, 1,500 millimetres; tail 140. Habitat : From the Persian Gulf and the coasts of India to China, Japan, and Papuasia. D. jerdonii. — Olive above, yellowish on the belly, with black cross-bands forming complete rings in young and half-grown 138 VENOMS specimens ; a black spot sometimes present between each pair of annuli. Total length, 910 millimetres ; tail 100. Habitat : Bay of Bengal, Straits of Malacca, Borneo. (7) Enhydris. Two large poison-fangs, and 2—4 small feebly grooved teeth. Body short and stout ; scales hexagonal or squarish, juxtaposed, disappearing almost completely on the belly. E. curtus. — Above with dark transverse bands, broadest in the middle ; end of tail black. Total length, 750 millimetres ; tail 75. Habitat : Coasts of India and Ceylon. Fig. 82. — Enhydrina valakadien (syn. E. bengalensis). THE PRINCIPAL SPECIES OF POISONOUS SNAKES ]89 (8 Enhydrina. Two large poison-fangs, followed by 4 solid non-grooved teeth. Body moderately elongate ; scales imbricate ; ventrals distinct but very small. E. valaJcadieii, (syn. E. hengalensis ; fig. 82). — Colour olive or grey, with black transverse bands, usually less distinct in the adult ; sides and belly whitish. Fig. 83. — Skull of Platiorus oluhrinus. (After G. A. Boulenger, op. cit.) Total length, 1,300 milhmetres ; tail 190. Habitat : From the Persian Gulf along the coasts of India and Burma, to the Malay Archipelago and Pdl^uasia. 140 VENOMS Fig. 84. — Platurus laticmidatus (syn. P. fisclieri). (After Sir Joseph Fayrer. ) (9) Aipysurus. Maxillaries a little longer th an the ectopterygoids ; poison-fangs moderate, fol- lowed, after a short interval, by 8—10 grooved teeth ; anterior mandibular teeth feebly grooved. Snout short ; head shields large, or broken up into scales. Body moderate ; scales im- bricate ; ventrals large, keeled in the middle. A. australis. — Brown, or cream-colour, with brown spots forming more or less distinct cross-bars. Total length, 930 miUi- metres ; tail 110. Habitat : Coasts of New Guinea and Australia. Other species of Aipy- SUEUS {A. eydouxii, annu- latus, and IcBvis) are found on the coasts of Singapore, Java, Celebes, and the Philippine and Loyalty Islands. (10) Platurus. (Figs. 83, 84.) Two large poison-fangs, and only one or two small solid teeth near the posterior extremity of the maxillary. Head shields large ; THE PBINCIPAL SPECIES OF POISONOUS SNAKES 141 nostrils lateral, the nasal shields separated by the internasals. Body greatly elongate ; scales smooth and imbricate ; ventrals and subcaudals large. Four species, distributed in the eastern parts of the Indian Ocean and in the Western Pacific. P. laticaudatus (syn. P. fischeri ; fig. 84). — Olive above, yellowish on the belly, with 29 — 48 black annuli. Total length : 970 milhmetres ; tail 90. Habitat: From the Bay of Bengal to the China Sea and the Western South Pacific Ocean. P. colithrinus (fig. 83). — Olive above, yellowish on the belly, with 28 — 54 black annuli, some or all of which may be interrupted below. Total length, 1,270 millimetres ; tail 125. Habitat : From the Bay of Bengal to the China Sea and the Western South Pacific Ocean. P. muelleri. — 62 black annuli, some of which are interrupted on the belly. Habitat : Only found in the South Pacific Ocean (subtropical zone), as far as the New Hebrides and the shores of Tasmania. P. schistorhynchus. — Coloration and size as in P. colubrinus ; body with 25 — 45 annuli. Habitat : Western Tropical Pacific. 142 VENOMS G.-GEOGRAPHICAL DISTRIBUTION OF THE I'lilNCIPAL GENERA OF POISONOUS SNAKES IN THE FIVE DIVI- SIONS OF THE WORLD. (1) EUBOFE. Families Sub-Pamiues Geneba CoLUBRiD^E Dipsadomorphince CcelopieUis ... ViPERiDvT! " Viperince . Viper a Geographical Area Borders of the Mediterra- nean in Franceand Spain ; Italy (only in Liguria). ^France, Italy, Switzerland, Austria- Hungary, Ger- many, Belgium, Sweden and Norway, Gt. Britain, Spain and Portugal, Bos- nia and Herzegovina, Southern Russia, Turkey and Greece. (2) ASIA. HydrojiJdi'nce COLUBRID^ Elapince ... / Hydrus Thalassopliis Acalyptopliis Hydrela2:)s j Hydrajjlds \ Distira Enhydris Enhydi'ina Aipysurus Platiiriis ' Bimgarus Naja HemibmiciarHS Callopliis ^ Doliojyhis Persian Gulf, Indian Ocean, ^ Bay of Bengal, Sti-aits r of Malacca, China Sea, Philippines, and Malay Archipelago. I India, Ceylon, Burma, Indo- china, Southern China, Dutch Indies, Borneo. India, Ceylon, Burma, Indo- China, Dutch Indies, Philippines. J South-eastern Asia, India, I Japan, Philippines, j South-eastern Asia, India, , - Burma. Indo-China, For- { mosa, Southern China. Indo-China, Malay Penin- sula. THE PRINCIPAL SPECIES OF POISONOUS SNAKES 143 ASIA.— {coutd.) Families Sub-Families Geneha Geographical Amea / Vqierince VlPERID.^: j Crotalince ] Pseudocerastes j Cerastes ^EcMs I Ancistr odov LacJiesis Turkestan, Ural, Siberia, Caucasus, Persia, Ar- menia, Western China, India, Ceylon, Hima- layas. Persia. Arabia, Palestine. Persia, Arabia, India, Balu- chistan, Afghanistan. Transcaspia, I'urkestan, Himalayas, Southern China, Formosa, Japan, Ceylon, Java. South-eastern Asia, India, Southern China, Indo- China, Formosa, Suma- tra. (3) AFRICA. ColubridjE Elapina Boulengerina- Ela2^ecliis ... Naja Sejpedon AsjndelajJs . . . Walterinnesia Homorelaps . . . * Dendrasjjis ... . Central Africa. Central and South Africa. J Egypt, Central and West -j Africa, Morocco, Congo, ( Angola. I South Africa, Cape of Good ( Hope. j South and South-east Af- ( rica, Mozambique. Egypt. South Africa, Cape of Good Hope. j Central and South Africa, ^- Angola, Great Lakes, Congo, Transvaal. 144 VENOMS AFRICA.— {contdi.) Families Sub-Families Gkneea Geographical Ahea ViPERiD^- Vvperina; ... .... f Causus Vi-pera Bit-is Cerastes Ecliis ... Atheris \ Atractaspis f West Africa, Gambia, Great -1 Lakes, Congo, Angola, i Transvaal. ( Morocco, Algeria, Tunis, I Egypt, Mozambique. Zanzibar, Zambesia, the Cape, Transvaal, Congo, the Gaboon, BengueUa, Angola, Senegal. Nigeria. North Africa, the Sahara. North Africa, Lake Chad, Soudan, Egypt, Somali- land, Socotra. j' Tropical Africa, Dahomey, Lagos, the Cameroons, the Gaboon, Congo. ^Tropical and South Africa, Congo, Angola, Lake Chad, the Gaboon, Da- homey, Gold Coast, Zan- zibar, SomaUland, Natal, and the Cape. ■1 THE PBINCIPAL SPECIES OF POISONOUS SNAKES 145 (4) OCEANIA. Families. Sub-Families. { HydropMince COLUBRID^ ^Elapinee ... ! .... Genbba. / Hydrus Thalassopliis Hydrela'ps ... Hyd,ro2}his Distira Enhydris Enhydrina Aipysurus Platuriis Ogmodon Glyphodon Pseudelapis Diemenia Pse^idech.is Denisonia MicropecJds Hoplocephalus Tropidechis NotecJiis Rhinliop locephn hi s Brachyaspis Acantliophis Elapogndtlius Rliynchelaps \ Furina Geographical Abea. ]i(inatonal aud Sub-troj)i- cal Pacific Ocean, the Moluccas, Papuasia, New Guinea, Celebes, Timor, Australia,Tasmania, New Caledonia, NewHebrides. Fiji Islands. I Northern Australia, New I Guinea. I Australia, th Moluccas, [ Papuasia. Australia, New Guinea. Australia, New Guinea. ( Austraha, Solomon Islands^ [ Tasmania. (New Guinea, Solomon Is- ( lands. Australia. Australia. Australia, Tasmania. Australia. Australia. j Moluccas, Papuasia, North- ( ern Australia. Australia. Australia. Australia. 10 146 VENOMS (5) AMEBIC A. Families. Scb-Pamilies. Geneba. •CoLtJBRiD^ Elapincc Elaps / Ancistrodon... Lachesis ViPERiDiE CrotalmcB .J siatrurus .. I Crotalus Geographical Auea. Mexico, Central America, Bolivia, Ecuador, Peru, Colombia. Brazil. (North America, Florida, Texas, Mexico, Guate- mala. Central and South Ameri- ca, Martinique, y t. Lucia. I North America east of the i Eockj' Mountains, Mex- ( ico. Southern Canada. British Columbia, Central Amer- ica, Guiana, Venezuela, Brazil, Uruguay, North- ern Argentina. 147 PART II. CHAPTER IV. SECRETION AND COLLECTION OF VENOM IN SNAKES. Non-poisonous as well as poisonous snakes possess parotid and upper labial glands capable of secreting venom. .In the former the organs of inoculation are wanting, but we shall see later on that the toxic secretion of their glands is just as indispensable to them as to the snakes of the second category for the purpose of enabling them to digest their prey. For the morphological, histological, and physiological demon- stration of the existence of these glands in harmless reptiles we are indebted to Leydig (1873), whose discovery has since been confirmed and extended by the researches of Phisalix and Ber- trand, Alcock, L. Rogers, and L. Lannoy. The parotids of Grass Snakes are mixed glands of the sero- mucous type. The serous tubes are situate almost exclusively in the posterior portion of the gland. As we proceed towards the anterior portion, we find that these serous tubes are interspersed with others which are exclusively mucous or sero-mucous, and they become entangled with those of the upper labial gland, properly so-called. The substance of the gland is divided into several lobes by bands of connective tissue ; the tubes are separated by septa of the same tissue, in extremely delicate layers (Lannoy). In poisonous snakes these glands are much more developed, especially in their hinder portions, which sometimes assume 148 VENOMS enormous dimensions. They may attain the size of a large ahnond {Crotalus, Naja), and they then occupy the spacious chamber ah-eady described (Chap. I., p. 10), which is situated behind the eye on each side of the skull. Each gland is surrounded by a thick capsule of fibrous tissue, two prolongations of which, the one anterior, the other posterior, keep it in its place beneath the masseter muscle. A portion of the latter is inserted in the capsule itself, in such a way that when the snake closes its jaws to bite, the gland is forcibly com- pressed and the contained liquid is squeezed into its excretory duct. Between the muscle and the envelope of the gland there is a serous pouch, which enables the one to slide over the other. The excretory duct runs along the outer side of the upper jaw, and opens by a slit at the base of the poison-fang, with which it inosculates at right angles in a little muscular mass forming a syhincter. In the normal position of repose, the poison-fang is always concealed by a gingival fold of mucous membrane, in the sub- stance of w^hich are buried a few fibres of the tendon of the internal pterygoid muscle. When the latter contracts, the tooth is almost completely exposed, and the efferent duct of the gland then assumes an oblique position, which allows of the direct dis- charge of the venom through the canal which runs along the greater portion of the length of the tooth. When the poison-faugs are folded back in their sheath, the poisonous secretion can escape freely into the buccal cavity by the slit situated at the base of the fangs. At the moment when the animal is about to bite, when it throws back its head and opens its jaws, directing its fangs for- wards, the muscles that come into action (masseters, temporals, and pterygoids) compress the glands on each side, and cause the venom to be expelled in a sudden jet, as if by a sort of ejaculatory process. In the case of certain species the venom may be projected to a distance of more than a yard. SECBRTION AND COLLECTION OF VENOM IN SNAKES 149 The quantity of venom secreted by the glands varies greatly, according to the length of time which has elapsed since the animal took its last meal, and in accordance with a nmnber of other con- ditions not very, easy to determine. The Common Viper of Europe yields scarcely 10 centigrammes of poison, while an adult Indian Cobra may excrete more than 1 gramme. Freshly collected venom is a syrupy liquid, citron-yellow or shghtly opalescent white in colour. When dried rapidly in vacuo or in a desiccator over calcium chloride, it concretes in cracked translucent lamellae like albumin or gum arable, and thus assumes a crystalloid aspect. In this condition it may be kept indefinitely, if protected from light, air, and moisture. It dissolves again in water just as readily as albumin or dried serums. I regularly weighed the dry residue from eleven bites made on a watch-glass by two Naja haje, received at my laboratory from Egypt at the same time, and placed in the same case. Both snakes were approximately of equal length, 1,070 millimetres. Through- out the entire course of the experiment, which lasted 07ie himdrecl and two days, neither of them took any food, but they drank water and frequently bathed. The results that I obtained are shown in the table on next page. It will be seen that in one hundred and two days, an adult Naja haje is capable of producing on an average 0*632 gramme of liquid venom, equal to a mean weight of 0'188 gramme of dry extract ; and we may conclude that 1 gramme of liquid gives 0"336 gramme of dry venom. In Australia it has been found by MacGarvie Smith, of Sydney, that Pseudechis por-pliyriacus yields at each bite a quantity of venom varying from O'lOO gramme to 0"160 gramme (equal to 0'024 gramme to 0"046 gramme of dry venom), and that a Hoplocephalus curt'us (Tiger Snake) yields 0 065 gramme to 0"150 gramme of 150 VENOMS liquid venom, with 0 017 gramme to 0-055 gramme of dry residue. In all the experiments of this physiologist, the proportion of dry residue varied from 9 to 38 per cent, of the liquid venom excreted by the reptile. A Lachesis lanceolatus (Fer-de-lance) from Martinique, of medium size, when both of its glands were squeezed, furnished me with 0"320 gramme of liquid venom, and 0*127 gramme of dry extract. NAJA HAJE I. NAJA HAJE II. Number of Weight of Venom Weight of Venom bite Date Fresh Dry Fresh Dry Gramme Gramme Gramme Gramme 1 April 20 ... 0-119 0031 2 „ 23 ... 0-151 0-043 3 May 14 ... 0-124 0-035 4 „ 21 ... 0132 0037 5 „ 28 ... 0-091 0019 6 June 2 0127 0-039 7 „ 19 ... 0-121 0043 8 July 1 ... 0-078 0-026 9 „ 2 ... 0-122 0-'o'48 10 „ 25 ... 0-111 0-034 11 „ 26 ... 0-679 0 021 Totals ... 0-581 0-174 0-684 0-202 Two large Cerastes vipers, from Egypt, yielded me, one 0*123 gramme, the other 0'085 gramme of liquid venom, which, after desiccation, left respectively 0 027 gramme and 0 019 gramme of dry residue. Under the same conditions, a magnificent Crotalus confluentus (Mottled Battle-Snake), for which I was indebted to the kindness of Mr. Eetlie, of New York, yielded, two months after reaching my laboratory, 0-370 gramme of hquid venom and 0*105 gramme of dry extract in a single bite. SECRETION AND COLLECTION OF VENOM IN SNAKES 151 The total quantity of liquid venom that I found contained in the two glands of the same reptile, when extirpated after deaths and after the snake had been in the laboratory for five months, amounted to 1"136 gramme, wbich gave 0'480 gramme of dry extract. We see, therefore, that the proportion of dry residue, including albumin, salts, the debris of leucocytes, and the toxic substance, oscillates between 20 and 38 per cent. Its strength varies with the length of time that has elapsed since the snake's last bite or last meal. From the histological standpoint, the process of the secretion of venom, in the cells of the glands, may be divided into two stages : — {a) A stage of nuclear elaboration. (b) A stage of cytoplasmic elaboration. These two stages are superposed and successive. In addition to the passive exchanges between the nucleus and the cytoplasm, the nuclear mass actively participates in the secre- tion. This participation is rendered evident : — (1) By the difference of chromaticity in the 'granules of chromatin. (2) By the emission of formed "granules into the cytoplasm, granules which are spherical and of equal bulk, with the chromatic reactions of differentiated intranuclear chromatin. (3) By the exosmosis of the dissolved nuclear substance, ac- cessorily formed in an ergastoplasmic shape. These formations constitute, on the one hand, the granules of venogen; on the other, th,e ergastoplasmic venogen. In the poison-cell of Vipera aspis, and in the serous cell of the parotid glands of Tropidonotus natrix (Grass Snake) the venogen is elaborated chiefly in granular form. On entering the perinuclear cytoplasm, the granule of venogen and the ergastoplasmic venogen may either disappear imme- VENOMS diately, as happens in periods ol:' cellular stimulation, or else continue to exist for some time within the cell, indicating a period of saturation by the elaborated material. During cytoplasmic activity the granule of venogen and the ergastoplasmic venogen disappear. Nuclear elaboration and cytoplasmic elaboration constitute two different cycles of secretion. The effect of the nuclear cycle is to furnish the cytoplasm with the elements necessary for the work of secretion properly so-called. Cytoplasmic elaboration is not confined to the basal protoplasm, but takes place throughout the entire cell : it is especially active in the perinuclear cytoplasm. The granule of venogen is distinguished from the granule of elaborated venom by its affinity for Unna's blue, safranin, and fuchsin. The granule of venom has an affinity for eosin; it is never excreted in granular form, but after intracellular dissolution. Venogen is never met with in the lumen of the gland-tube.^ Collection of Venom. Venom can be extracted from the poison-glands of either freshly killed or living snakes. In cases in which the venom of dead snakes has to be collected, the best method of extraction consists in fixing the head of the animal to a sheet of cork and carefully dissecting out the gland on each side. The reptile being placed on its back, the lower jaw is removed with a pair of scissors ; two strong pins or two tacks are thrust through the skull, in the median line, in order to keep the head from moving. The poison-fangs are next drawn out of their sheaths, and, without injuring them, the two poison-ducts, which open at their bases, are isolated and tied with a thread in order to prevent the poison from running out. The dissection of the glands is then very easy ; they are lifted ' L. Lannoy, "These de doctorat es sciences," Paris, 1903, No. 1,138, serie A, 454. SEGEETION AND COLLECTION OF VENOM IN SNAKES lf,y out and placed in a saucer. The end of the duct is cut between the gland and the ligature, and with a pair of fenestrated or polypus forceps the whole of the glandular mass is gently squeezed from behind forwards, the liquid which flows out being received in a large watch-glass. If pressed for time, a more simple method of operating is to hold the head of the snake in the left hand, with the mouth open and the lower jaw directed downwards. A watch-glass, capsule, or receptacle of some sort, such as a cup or plate, is then introduced by an assistant between the jaws, and, with the index finger and thumb of the right hand, the whole of the region occupied by the glands on each side of the upper jaw is forcibly compressed from behind forwards ; the poison flows out by the fangs. The extraction of the venom from living snakes is effected in the same manner. The animal being firmly held by the neck, as close as possible to the head, so that it cannot turn and bite ; it can be made to eject the greater portion of the liquid con- tained in its two glands by compressing the latter with force from behind forwards, as one would squeeze out the juice from a quarter of an orange (fig. 85). It is necessary to take care that the reptile cannot coil itself round furniture or other objects in the vicinity of the operator, for if this should happen there would be the greatest difficulty in making it let go, especially if dealing with a strong animal such as a Cobra, Eattle-Snake, or Fer-de-lance. Snakes of the last-mentioned kind are especially difdcult to manage. In order to avoid the risk of being bitten, it is always wise to begin by pinning down the head of the animal m a corner of its cage by means of a stick, and to seize it with a pair of long fenestrated tongs shaped like forceps, ^ The operator then easily draws the reptile towards him and grasps it firmly by the neck with his left hand, always as close to -the head as possible, at the same time raising the body quickly in order to prevent it from taking Fig. 85.— Collecting Venom fkom a Laclmis at the Serotheeapedtic Institute AT Sao Paulo (Beazil). SEGBETION AND COLLECTION OF VENOM IN SNAKES 155 Fig. 86. — Chloroforming a Cobra in order to Collect Venom, at the French Settlement of Pondicherry, in India (Stage I.). 156 VENOMS hold of anything. In this way the most powei'ful snake is per- fectly under control. At Pondicherry, where is collected the greater portion of the venom of Naja tripudians used by me for the vaccination of the horses that produce antivenomous serum, it is customary to chloro- form the snakes in order to render them easier to manipulate. The reptile is placed in a lai'ge covered jar, containing a pad of absorbent wool impregnated with chloroform (figs. 86, 87), and in a few minutes it is stupefied. It is then grasped by the neck with the hands, and the edge of a plate is slipped between its jaws. On compressing the two poison-glands with the fingers, the venom dribbles out on to the plate. A detailed description of this technique will be found in a note kindly drawn up for me by my friend Dr. Gouzien, late head of the Medical Staff of the French Settlements in India, and reproduced further on in the section of this book devoted to documents. The note in question was accompanied by figs. 17, 18, 19, 86, 87, and 88, which are reproduced from photographs, for which I am indebted to th(3 kindness of M. Geracki, Engineer of the Savanna Spinning Mill at Pondicherry, Dr. Lhomme, and M. Serph, Assistant Surgeon-Dispenser. The collection of the venom liaving been completed, the snake is put back into its cage again, the tail and the body being intro- duced first, and then the head. The lid or trap-door is half closed with the left hand, and, with a quick forward thrust, the right hand releases its grasp of the reptile and is immediately withdrawn ; at the same time the left hand completes the closure of the cage. The snake is temporarily dazed, as though stunned, and it is only after the lapse of a moment that it thinks of darting open-mouthed at tlie walls of its prison. When it is desired to procure large quantities of venom, as is indispensable in laboratories where antivenomous serum is pre- pared, the endeavour must be made to keep the snakes alive for the longest possible time. It then becomes necessary to resort SECRETION AND COLLECTION OF VENOM IN SNAKES 157 to artificial feeding in the manner previously described (see p. 17), for they very often refuse to feed themselves. Except vi^hen a snake is moulting, the venom can be extracted from its glands about every fortnight ; and it is better that the extraction be not performed concurrently with artificial feeding, Fig. 87.— Chlgiiofobming a Cobba in ordeb to Collect Venom, at the French Settlement op Pondicherby, in India (Stage II.). since, owing to the fact that the venom serves the animal as digestive juice, the reptile will soon perish if deprived of the means of digesting the food that it is obhged to receive. It is best, therefore, to select one day of the week for artificial feeding, and the corresponding day of the following week for the extraction of the venom. When the venom has been collected, it must immediately be 158 VENOMS placed ill a desiccator over calcium chloride or sulphuric acid, in order to dry it rapidly. In hot countries, and where no laboratory specially equipped for the purpose exists, it will suffice to dry the venom in a current of air, or even in the sun. It then concretes in scales of a citrin colour, more or less dark, according to the concen- PiG. 88. — Collecting Cobea Venom at Pondichekey (Stage III.). tration of the liquid. In this dry condition, placed in well-corked bottles, protected from damp air, it may be kept almost indefinitely without losing anything of its original toxic power. On the con- trary, if the desiccation be imperfect it undergoes a somewhat rapid change, and assumes a disagreeable odour of meat peptone. I have kept samples of various venoms, dried as described, for fifteeii years without any sensible diminution of their activity. 159 CHAPTER V. THE CHEMICAL STUDY OF SNAKE-VENOMS. In the condition in which they are received on issuing from the glands, venoms always present the appearance of a thick saliva, of an oily consistency and more or less tinged with yellow, according to the species of snake by which the poison has been produced. They are entirely soluble in water, the addition of which renders them opalescent. Tested with litmus they exhibit a slightly acid reaction ; this acidity, which is due to the presence of a very small quantity of an indeterminate volatile acid, dis- appears on desiccation, so that solutions of dried venom are neutral. The taste of venoms is very bitter. Their density, which is slightly greater than that of water, varies from 1030 to 1050. Venoms are composed of a mixture, in variable proportions, of proteid substances, mucus and epithelial debris, fatty matters and salts (chlorides and phosphates of lime, ammonia and magnesia), with from 65 to 80 per cent, of water. The elementary analysis of Cobra-venom made by H. Arm- strong^ gave the following results : — Carbon 43'04 per cent. Hydrogen 7-00 „ Nitrogen 12-45 „ Sulphur 2-50 Eesidue Small quantities. Not much is to be learnt from these figures ; it would be of far greater importance to know the exact constitution of the ' " Snake Commission Eeport," 1874. 160 VENOMS proteid substances to which venom owes its pliysiological pro- perties. Unfortunately, our knowledge of the chemistry of tiie albuminoid matters is still too imperfect for it to be possible for us to determine their nature. As early as 1848 it was pointed out by Lucien Bonaparte that in the venom of Vipera hems the most important principle is a proteid substance to which he gave the name of viperin or echidnin, and which he compared to the digestive ferments. Later on Weir Mitchell and Eeichert, and subsequently Norris Wolfenden, Pedlar, Wall, Kanthack, C. J. Martin, and MacGrarvie Smith, showed that venoms, like diastases, exhibit a great com- plexity in composition; that all their characteristic toxic constit- uents are precipitable by absolute alcohol, and that the precipitate, when redissolved in water, recovers the properties possessed by the venom before precipitation. According to Armand Gautier,^ venoms contain alkaloids. The latter may be obtained, in very small amounts, however, by finely pulverizing dried venom with carbonate of soda, and systematically exhausting the mixture with alcoholic ether at a temperature of 50° C. These alkaloids have yielded crystallized chloraurates and chloroplatinates, and slightly deliquescent crystallized chlorhy- drates. The latter produce Prussian blue when treated with very dilute ferric salts, and mixed with a little red prussiate. They therefore represent reductive bodies analogous to ptomaines. Norris Wolfenden did not succeed in extracting these alkaloids from Cobra-venom, whence they had nevertheless been isolated by Armand Gautier. Wolcott Gibbs, and afterwards Weir Mitchell and Eeichert, likewise failed to find them in Crotalm- venom. The toxicity of these bases is, moreover, but very slight, for the totality of the alkaloids extracted by A. Gautier from 0'3 gramme of Cobra-venom did not kill a small bird. It is therefore to the toxalhumins that the toxic properties of venoms are essentially due. ' Bulletin dc VAcadcmie do Medecine, t. x., 1883, p. 947. THE CHEMICAL STUDY OF SNAKE-VENOMS 161 All venoms are not equally affected by heat. The venoms of CoLUBRiD^ {Naja, Bungarus, Hoplocephalus, Pseudechis) and those of the Hydrophiid^ are entirely uninjured by temperatures approaching 100° C, and even boiling for a short time. AVhen the boiling is prolonged, or when venoms are heated beyond 100" C, their toxic power at first diminishes, and then disappears altogether. At 120° C. it is always destroyed. The venoms of ViPERiDiE {Lachesis, Grotalus, Vipera) are much less resistant. By heating to the coagulating point of albumin, i.e., to about 70° C, their toxic properties become attenuated, and they are entirely suppressed between 80° and 85° C. Z/ac/ims-venoms are the most sensitive ; their toxicity is lost if they be heated beyond 65° C. On separating the coagulable albumins of the venoms of CoLU- BRID^, by heating to 72° C, followed by filtration, we obtain a perfectly limpid liquid, which is no longer injured by boiling, and in which the toxic substance remains wholly in solution. The albuminous precipitate, when separately collected and washed, is no longer toxic. The clear liquid, after being filtered, is again precipitated by absolute alcohol, and the precipitate, redissolved in an equal quantity of water, is just as toxic as the original filtered liquid. The venoms of ViPERiDiE, when coagulated, by heating them to a temperature of 72° C, and filtered, are almost always inert. The albuminous coagula, if washed, redissolved in water, and injected into the most sensitive animals, produce no harmful effect whatever. The results of dialysis likewise differ when we experiment with the venoms of Colubrid^ and Vipbrid^. The former pass slowly through vegetable membranes, and with greater difficulty through animal parchment. The latter do not dialyse. Filtration through porcelain (Chamberland caudle ¥) does not sensibly modify the toxicity of the venoms of CuLUBiUDiE ; 11 162 VENOMS on the contrary, it diminishes that of the venom of ViPERiDiE by nearly one-half. By using a special filter at a pressure of 50 atmospheres, C. J. Martin has succeeded in separating from the venom of an Austrahan Pseiulechis two substances : a non-diffusible alhiimi)ioid, coagulable at 82° C, and a diffusible, non-coagulable alhumose. The former produces haemorrhages ; the second attacks the nerve-cell of the respiratory centres. All venoms exhibit most of the chemical reactions characteristic of the proteids : — Millon's reaction. Xantlio-pr oleic reaction (heating with nitric acid and subsequent addition of ammonia = orange coloration). Biuret reaction (caustic potash and traces of sulphate of copper). Precipitation by picric acid, disappearing on being heated, re- appearing w^hen cooled. Precipitation by saturation with chloride of sodium. Precipitation by saturation with sulphate of magnesium. Precipitation by saturation with ammonium sulphate. Precipitation by a 6 per cent, solution of sulphate of copper. Precipitation by alcohol. According to C. J. Martin and MacGarvie Smith, the albumoses of the venoms of Colubeid^ are hetero-albumoses, proto-albumoses, and perhaps deutero-albumoses in small quantities. They can be separated in the following manner: — The solution of venom is heated to 90° C, and filtered in order to separate the albumins coagulable by heat. The filtrate, saturated with sulphate of magnesium, is shaken for twelve hours. By this means there is obtained a flocculent precipitate, which is placed upon a filter and washed with a saturated solution of sulphate of magnesium. The filtrate is dialysed for twenty-four hours in a stream of distilled water, and then concentrated, likewise by dia- lysis, in absolute alcohol. Thus we obtain a few cubic centimetres THE CHEMICAL STUDY OF SNAKE-VENOMS 163 of liquid, which contains a small quantity of protetds in solution. These proteids can be nothing but a mixture of proto- and deutcro- albumoses with peptones. That there is actually no trace of the latter can easily be ascertained. Neumeister^ has shown that it is impossible to precipitate all the proto-alhumoses of a solution by saturation with neutral salts, and, since the filtrate becomes slightly turbid when a few drops of a 5 per cent, solution of sulphate of copper are added to it, we must conclude that it contains a small proportion of these proto- alhmnoses. The deposit retained upon the filter after washing with sulphate of magnesium is redissolved in distilled water, and dialysed for three days. An abundant precipitate then becomes collected in the dialyser. This is centrifuged. The clear liquid is decanted with a pipette, then concentrated by dialysis in absolute alcohol, and finally evaporated at 40° C. until completely desiccated. The solid residue is washed and centrifuged several times in distilled water, after which it is dried on chloride of sodium. This method enables us to separate two albumoses, both pre- cipitable by saturation with sulphate of magnesium, and belonging to the class of primary albumoses : one of these, proto-albiimose, IS soluble in distilled water, the other, hetero-albumose, is insoluble ; but the latter can be dissolved in dilute solutions of neutral salts. These bodies are respectively identical with those obtained by the pepsic digestion of proteids.- In order to study separately the local and general effects of these different albumoses, C. J. Martin and MacGarvie Smith performed the following experiment : — They introduced beneath the skin of the belly of a guinea- pig, previously shaved and rendered aseptic, two small pieces of sterilized sponge, about 2 c.mm., one of which was impregnated ' Zuitschrifl fiir Biologic, xxiii. Kiihne and Chittenden, " Ueber Albumosen," ZeUschrift fiir Biolocjic, 1884. 164 VENOMS with the solution of proteid, while the other sei'ved as control. The two small incisions, one on either side of the median line, were then sutured and covered with collodion. In this way the maximum of local effect and the minimum of general effects was obtained. The solutions of albumoses introduced by this method into the organism produced an enormous oedema, which, in from six to eight hours, extended along the whole side of the abdomen containing the sponge charged with poison. To test the general toxic effects, the solutions were injected into a vein or into the peritoneal cavity. It was thus found that the jyroto- and hetero-alhiiinoses killed the animals in a few hours. It must therefore be concluded from these facts that the active principles of venom are proto- and hetero-albumoses, the albumins that it contains being devoid of all toxic power. Many chemical substances modify or destroy venoms, and we shall see in another chapter that several of them, by reason of their properties, may be very usefully employed for the destruction, in the actual wound resulting from a venomous bite, of the venom that' has not yet been absorbed in the circulation. Among these substances the most important are : — A 1 per cent, solution oi permanganate of potash (Lacerda). A 1 per cent solution of chloride of gold (Calmette). Chloride of lime or even hijpocUoride of calcium (Calmette), in a solution of 1 in 12, which is augmented, at the moment of use, by 5 to 6 volumes of distilled water, so as to brmg it to the standard strength of about 850 cubic centimetres of active chlorine per litre of solution. A 1 per cent, solution of chromic acid (Kaufmann). Saturated hromized water (Calmette). A 1 per cent, solution of trichloride of iodine (Calmette). All these chemical bodies also modify or destroy the diastases and the microbic toxins. The venoms, although more resistant to the influence of heat, behave, therefore, like these latter, and exhibit the closest afhnity with them. Moreover, like all the THE CHEMICAL STUDY OE SNAKE-VENOMS normal glandular juices, they possess very manifest zymotic pro- perties, which singularly complicate their physiological action, and upon which we shall dwell later on. Electricity, employed in the form of continuous electrolytic currents passing through a solution of venom, destroys the toxicity of the latter, because under these conditions there is always formed, at the expense of the salts accompanying the venom, a sufficient quantity of chlorinated products (hypochlorites, chlorates, &c.), and a small amount of ozone, the oxidizing action of which is extremely powerful. With alternating currents of high frequency, Phisalix, repeating the experiments that Arsonval and Charrin had performed upon diphtheria toxin, thought that he had succeeded in attenuating venom to the point of transforming it into vaccine.^ But it has been shown by Marmier that this attenuation was simply the result of thermic actions. When, by means of a suitable arrangement, any rise of temperature was carefully avoided, no modification of toxicity was obtained.^ The influence of UgJit, which has no effect upon venom pre- served in a dry state, is, on the contrary, very marked upon venom in solution. Solutions of venom that are destined for physiological experiments should therefore not be employed without controls, if they be several days old. Apart from the fact that, if care be not taken to render them aseptic, they very soon become con- taminated with the germs of all kinds of microbes, it is found that they gradually lose a large part of their activity, especially when they remain in contact with the air. By filtering them through a Chamberland candle and keeping them in the dark, in a re- frigerator, in perfectly closed phials, they may be kept unimpaired for several months. ' Coviptes rendiis de la Socicla de Biologic, 29 fevrier, 1896. - Annalea dc I'Institut Pasteur, 1896, p. 489. 166 VENOMS The addition of glycerine in equal parts to a concentrated solution of venom is also an excellent means of preservation. Phisalix has shown that the emanations from radium attenuate and then destroy the virulence of Cobra- and also of Viper-venom. "Dry Viper-venom, dissolved in aqua chloroformi in the pro- portion of 1 in 1,000, is put up in four tubes, three of y^Ynch are irradiated, the first for six hours, the second for twenty hours, and the third for thirty-six hours. Three guinea-pigs, of equal weight, are inoculated with equal quantities of the irradiated venom ; a control receives the non-irradiated venom. The latter dies in ten hours ; the animal inoculated from the first tube dies in twelve hours ; the one inoculated from the second tube in twenty hours, and the third proves resistant without any symptom of poisoning. A second inoculation produces a transitory lowering of the animal's temperature by half a degree. At the end of four days it dies after inoculation with a lethal dose." The nature of the solvent exerts a great influence upoii the action of the emanations from radium : if the same experiment be performed with venom dissolved in a 50 per cent, mixture of glycerine and water, the attenuation is merely relative after six hours. Auguste Lumiere and Joseph Nicolas, of Lyons, conceived the idea of studying the effect upon venom of the prolonged action of the intense cold produced by the evaporation of liquid air.^ The Cobra-venom employed by these investigators was in solution at a strength of 1 in 1,000. It was submitted to the action of liquid air, partly for twenty-four hours and partly for nine days at - 191° C. Its toxicity was in no way diminished. Lastly, I must mention the recent researches of Hideyo ^Province medicale, 21 Septembre, 1901. THE CHEMICAL STUDY OE SNAKE-VENOMS 167 Nogucbi,' with reference to the photodynamic action of eosin and erijthrosin upon the venoms of the Cobra, Vipera riissellii, and Crotahis. It was found by the scientist in question that the toxicity of these various venoms is more or less diminished in the presence of these anihne colours, when the mixtures are insolated. Cobra-venom is the most resistant, just as it is in regard to the other physical or chemical agents. That of Crotahis, on the contrary, is the least stable. ' Eockefeller Institute for Medical Research, New York, 1906. 1(5K CHAPTER VI. THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS. A. — Physiology of Poisoning in Man and in Animals Bitten BY THE Different Species of Poisonous Snakes. {Coluhrida ; Viperidce ; Hijdrophiidce.) The bites of poisonous snakes produce very different effects according to the species of snalve, the species to which the animal bitten belongs, and according to the situation of the bite. It is therefore necessary to take these various factors into account, in describing the symptoms of poisoning in different animals. When the quantity of venom introduced into the tissues by the bite of the reptile is sufficient to produce fatal results — which is happily not always the case— ^e venom manifests its toxic action in two series of phenomena : the first of these is local and affects only the seat and surroundings of the bite; the second, or general series, is seen in the effects produced upon the circulation and nervous system^ It is remarkable to find how great is the importance of the local disorders when the venomous reptile belongs to the Solenoglypha group (ViPEEiDiE), while it is almost nil in the case of the Protero- glypha (CoLUBRiD^ and HYDROPHiiDiE). The effects of general intoxication, on the contrary, are much more intense and more rapid with the venom of Proteroglypha, than with that of Solenoglypha. In consideririg the usual phenomena of snake-poisoning in man , we must therefore take this essential difference into account, and THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS 169 draw up separately a clinical description of the symptoms observed after a bite from a Cobra (Colubridz3), for instance, and another list of those that accompany a bite from Lachesis or Vipera berus (ViPERIDiE). The bite of a Cobra, even of large size, is not very painful ; it is characterized especially by numbness, that supervenes in the bitten part, rapidly extends throughout the body, and produces attacks of syncope and fainting. The patient soon experiences a kind of lassitude and irresistible desire to sleep ; his legs scarcely support him ; he breathes with difficulty and his respiration becomes of the diaphragmatic type. By degrees the drowsiness and the difficulty of breathing become greater ; the pulse, which at first is more rapid, becomes slower and gradually weaker, the mouth contracts, and there is profuse salivation, the tongue appears swollen, the eyelids remain drooping, and, after a few hiccoughs frequently accompanied by vomiting and involuntary emissions of urine or faecal matter, the unfortunate victim falls into the most profound coma and dies. The pupils react to luminous impressions up to the last moment, and the heart continues to beat sometimes for two hours after respiration has ceased. All this takes but a few hours, most frequently from two to six or seven, rarely more. "When the reptile by which the bite is inflicted is one of the Solenoglypha, such as a Lachesis for example, the seat of the bite immediately becomes very painful and red, then purple, ^^he surrounding tissues are soon infiltrated with sanguinolent serosity" Sharp pains, accompanied by attacks of cramp, extend towards the base of the limb. The patient complains of intense thirst, and extreme dryness of the mouth and throat ;Uhe mucous membranes of the eyes, mouth, and genitalia become congested^ These phenomena often continue for a very long period, even for more than twenty-four hours, and^re sometimes accompanied by haemorrhages from the eyes, mouth, stomach, intestines, or bladder, and by more or less violent dehriui^ 170 VENOMS If the quantity of venom absorbed be sufficient to cause death, the patient exhibits, a few hours after being bitten, stupor, insen- sibiUty, and then somnolence, with increasing difficulty of respira- tion, which ends by becoming stertorous. Loss of consciousness seems complete a good while before coma appears. Asphyxia then ensues, and the heart continues to beat for nearly a quarter of an hour after respiratory movements have entirely ceased. In certain exceptional cases death is very rapid ; it may super- vene suddenly in a few minutes, even before the local phenomena have had time to manifest themselves ;Qn this case the venom, having penetrated directly into a vein, has produced almost imme- diate coagulation of the blood, thus causing the formation of a generalized embolisno^ If the venom be introduced in a highly vascular region, or directly into a vein, the result is almost invariably fatal. On the contrary, if the derm be scarcely broken, or if the clothing has acted as a protection, scarcely any absorption will take place. We are here confronted with the same factors of gravity as in the case of bites inflicted upon human beings by animals suffering from o-ahies. In experiments we are able to eliminate all these factors, and to follow in an animal inoculated with a known quantity of venom the whole series of phenomena of poisoning, the intensity of which can be graduated. Let us see, then, how the various animals that it is possible to make use of in laboratories behave with regard to venoms of different origins. B. — The Physiology of Expeeimental Poisoning. In the monkey, the first apparent sign of the absorption of (7o&?-a-venom, or of the venom of any other species of Colcbrid^, is a sort of general lassitude ; the eyelids next become half closed. The animal appears to be seeking a suitable spot in which to rest ; it gets up again immediately, and walks with a jerky action ; its THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS 171 limbs have a difficulty in supporting it. It is soon attacked by nausea, vomiting and dyspncea ; it rests its head upon the ground, raises it, trying to get breath, and carries its hand to its mouth as if in order to pluck a foreign body from its throat. It totters upon its limbs, and lies down upon its side with its face against the ground. Ptosis increases, aud complete asphyxia soon supervenes. The heart continues to beat for some time after respiration has ceased, and then stops in diastole. Cadaveric rigidity very rapidly sets in, and persists for a long time, even after putrefaction has commenced. During the last moments of life the pupil remains very sensitive ; the animal appears to retain unimpaired its sense of hearing and sensibility to pain. The electi'ic excitability of the muscles of the face per- sists, but that of those of the limbs and body almost entirely disappears. The application of volta-faradic currents from the nape to the diaphragm produces no respiratory movement when asphyxia begins to manifest itself. The sphincters of the bladder and anus relax after a few spasms, which, in case of males, fre- quently provoke the ejaculation of semen ; the urine and faeces immediately escape. The autopsy reveals shght hsemorrhagic oedema at the point of inoculation, and hypersemia of all the viscera, especially of the liver and spleen, with, very frequently, small haemorrhagic patches on the surface of these organs, and on that of the intestine and kidneys. The serous membranes, especially the meninges, endo- cardium, pleurfe, and peritoneum, exhibit ecchymoses ; the lungs are besprinkled w^ith small infarcts, the more numerous the slower the intoxication. The blood remains fluid and laccate. In poisoning by the venoms of Viperid^, the hsemorrhagic always preceded by a period of asphyxia, indicating that the bulbar nuclei of the pneumogastric nerve have become affected. At the autopsy, however, [the blood, instead of remaining fluid, is always phenomena appear Death is 172 VENOMS found to be coagulated into a mass in all the vessels ; it afterwards gradually becomes redissolved in six or eight hours, and then appears laccate, as after poisoning by C'o&ra- venom, but darker?} All mammals exhibit the same symptoms after inosulationjKilh lethal doses of venoiBu___The same applies to birds: but in the latter the period of asphyxia^ is much longei-, probably on account of the reserves of air jiccumulated in their^air-sacs^and pneumatic bones. They gape like pigeons that are being suffocated, rest the tip of the beak on the floor of the cage, and frequently have con- vulsive spasms of the pharynx, accompanied by flapping of the wings. Small birds and even pigeons are extremely sensitive to venom ; fowls are more resistant. Frogs, thanks to their cutaneous respiration, succumb very slowly. I have seen some survive for thirty hours after being inoculated with a quantity of venom which, when subcutaneously injected into a rabbit, causes death in ten minutes. Lizards and chameleons succumb very rapidly. Grass Snakes and non-venomous snakes in general withstand doses of venom that in proportion to their weight are fairly large nevertheless, as indeed we shall see in the sequel, they do not possess any real immunity. It is only poisonous snakes that are unaffected by enormous doses of their own venom, as has ah-eady been shown by Fontana, Weir Mitchell, and Viand Grand Marais. They are, however, quite capable of being poisoned by snakes belonging to altogether different species ; strong doses of Crotalus- or Lachesis- venom are fatal to Cobras or Kraits, and, when several poisonous snakes are shut up together in the same cage, they are not in- frequently seen to kill each other as the result of repeated bites. Fishes, which are particularly sensitive to the venom of Hydro- PHiiDiE, readily succumb to inoculation with other venoms, such as that' of the Cobra. At Saigon, in 1891, I made experiments upon the action of this latter venom on two specimens of the THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS 173 fiobtins fishes, that the natives of Annam rear in aquariums in too ' order to witness their combats and make bets on them. The fishes died five hours after intramuscular inoculation v^^ith a dose which kills a pigeon in twenty minutes. Many invertebrates, such as leeches, crayfish, and gastropod molluscs (snails), are killed by inoculation with very small quantities of venom. C. Dkteumination of the Lethal Doses of Venom fok Different Species of Animals. It is very difficult to specify, even within broad limits, the dose of venom necessary to kill a human being. The quantity of poison introduced by the bite of a venomous snake depends, as has already been stated, upon a large number of factors, and, very fortunately, this quantity is not always sufficient to cause death. Thus in India, that is to say in the region in which snakes are most numerous andi most dangerous, the mean mortahty seems scarcely to exceed 35 to 40 per cent., so far as it is possible to judge from official statistics. But, by experimenting upon animals, and com- mencing with known doses of venom, which has^rst been dried and then dissolved again in always the same quantity of physio- logical saline solution or sterile distilled water, we can determine exactly, /or each kind of venom and for each species of animal, the minimum lethal dose 'per Tiilogramme of animalj The entire series of data collected by investigators who have devoted themselves to this study may be summed up as follows :— Minimal doses lethal in twenty-four hours for a guinea-pig weighing from 600 to 700 grammes :-- COLVBRID^, Venom of Naja tripudians 0-0002 gramme ,, Bungarus cceruleuH 0'0006 ,, ,, Naja haje ... ... ... ... 0'003 „ 174 VENOMS VIPEBIDJE. Venom of Vipera herus 0 04 gramme , Vixiera riissellii {Dahoia) ... O'OOI „ ,, Lachesis lanccolatus ... ... 0'02 „ ,, Lachesis mutus {Sttrucucii) ... 0'02 „ ,, Lachesis nemviedii (Urutu) ... 002 „ „ Lachesis flavoviridis ... ... 0 007 „ ,, Ancistrodon contoririx ... ... O'OIS „ Co6ra-venom. Dose lethal in twenty-four hours for different animals : — Dog ... Rabbit Guinea-pig Eat ... Mouse Frog O'OOOS gramme per kilogramme 0-0005 0-0004 0 0001 ,, 150 grammes 0-000003 „ 25 0-0003 „ 30 Venom of Bungarus ccendeiis (Common Krait), according to Elliot, Sillar, and Carmichael.^ Minimal lethal doses for : — Fi'og Eat Eabbit (by subcutaneous injection) Eabbit (by intravenous in- jection, according to G. Lamb) 0-0005 gramme 0-001 0-00008 „ per kilogramme 0-00004 Venom of Enhydrina valakadien (according to Elliot and Eraser).- Minimal lethal doses per kilogramme : — Eat Eabbit Cat 0-00009 gramme 0-00006 „ 0-0002 Venom of Enhydris curtus : — Eat . . . 0-0005 to 0-0006 gramme per kilogramme ' Five. Boy. Soc, Loudon, l.Kxi\-., 1904, pp. 108-109. -' Ibid., pp. 104-108. THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS 175 Venom of Notechis scutatus (syn. Hoplocepludas curtus ; the Tiger Snake of Australia) : — Babbit (by intravenous in- jection, according to Tidswell) ... 0 00006 gramme per kilogramme Venom of Vipera rassellii (Daboia) : — Babbit (by intravenous in- jection, according to G. Lamb) O'OOOOS gramme per kilogramme Venom ol Lachesis gramineus (Green Pit- Viper, India) : — Babbit (by intravenous in- jection, according to G. Lamb) ... ... ... 0'002 gramme per kilogramme Venom of Crotalus adamanteus (Californian Eattle-Snake) : — Babbit (by intravenous in- jection, according to Mc- Farland, G. Lamb, and Flexner and Noguchi) ... 0-00025 gramme per kUogramme It will have been seen from the foregoing figures, that the respective sensitiveness' of the dog, cat, rabbit, guinea-pig, rat, mouse, and frog, with regard to the same venom, is in no way- proportional to the weight of these animals. The species mentioned are, per unit of weight, more or less resistant to intoxication ; and, on experimenting with other animals, as for instance the monkey, pig, ass, and horse, we find that the monkey is much more susceptible to intoxication than the dog, and that the ass is extremely sensitive (0"010 gramme of Cobra- venom is sufficient to kill it), while the horse is less so, and the pig is by far the most resistant. The same weight of dry Cobra-venom, let us say 1 gramme to be precise, will enable us to kill 1,250 kilogrammes of dog, 2,000 kilogrammes of rabbit, 2,500 kilogrammes of guinea-pig, 1,430 kilogrammes of rat, or 8,333 kilogrammes of mouse. 176 VENOMS The lethal dose for a horse being, as I have ascertained by iny own experiments, about 0"025 gramme, 1 gramme of dry Cobra- venom will therefore suffice to kill 20,000 kilogrammes of horse. Assuming that man, in proportion to his weight, possesses a resistance intermediate between that of the dog and that of the horse, we may consider that the lethal dose for a human being is about 0'015 gramme. It follows, therefore, that 1 gramme of venom would kill 10,000 kilogrammes of man, or, let us say, 165 persons of an average weight of 60 kilogrammes. Another extremely important fact, which must not be lost sight of, is that differences of toxicity, which are often considerable, are exhibited by the venoms of different specimens of the same species of snake, or by the venom of the same snake collected at different times. I have found, for instance, in the case of the specimens of Naja and LacJiesis reared in my laboratory, that, according to the length of time that the animals had been without food, and to the nearness or otherwise of the moulting period, the venom was more or less active, and that on evaporation it left behind a more or less considerable quantity of dry extract. In certain cases, immediately after the moult and after a prolonged fast, the venom w^as ten tiines more active than after a plentiful meal or before the moult. The figures given above must therefore not be regarded as determining the minimal lethal doses of the different venoms, except in a purely comparative way, and they must be considered only as data useful to know when it is desired to experiment upon animals with these substances. Variations of this kind are observed in the case of all species of snakes. Thus Phisalix rightly insists upon the necessity of always noting, besides the species of snake, the place of origin and the season ; for he has himself seen that, as regards French vipers, those of the Jura, for example, produce in the spring a venom almost devoid of local phlogogenic action; while vipers from the vicinity of Clermont-Ferrand, though less toxic, produce much more serious local effects. THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS 177 On the other hand, it has been shown by Th. Madsen and H. Noguchi, in a very interesting study of venoms and anti- venoms,^ that, when we examine the relation between dose and toxicity, we find 'that the interval separating the moment of inoculation from that of death diminishes only up to a certain point in proportion as the dose is increased. In the case of the guinea-pig, with 0-0005 gramme of Cobra-venom the interval is 3 hours 75 seconds ; but after this, an increase in the dose produces only a relatively inconsiderable acceleration of death. There is therefore no strict ratio between the dose inoculated and the time that elapses until death supervenes. X). Effects of Venom in Non-lethal Doses. When the quantity of venom introduced into the organism is insufficient to cause death, the phenomena that precede and accompany recovery differ very greatly according as the snake from which the venom was derived belongs to the Colubeid^ or ViPERIDiE. After a non-lethal bite from a Coira or Krait, for example, convalescence usually takes place very rapidly, and, apart from the local oedema ofJhe_subci]^^ "whicFlirver^ leads to the-fomia.tion.oI-a. suppuraiing ( jbscess, no pasting , J.niur^i-Jia- health__is_ab. The venom | \ is eliminated-bjL-tbe-kidaeys,--:adiliQut even causing albuminuria, and sensationgraduallv returns. iiL±a[anJ..v-four or forty-eight hours, in the part affected by the_originajJesion. If the bite has been inflicted by a Viperine^siiake, the local lesion, which is much more extensive^^aJmosWl^^ ] formation ojj;jaich_o^jangrene. Haeniflrxhiiges-ij-Qrixih^-nmcQ^ membranes, an.d sanguineous suffusian^i-B-te-1^h-e--se-ye-u-&--Gadii£a^ ' " Communication de I'lnstitut S^rotherapique de I'Etat danois," tome i., Copenhagen, 1906. 12 178 VENOMS such as the pleura__or pericardium, may supervene more or less s^owTy: Pulmonary infarcts' are sometimes .,produced,__as_ well as desquauiationand haeni()ii]i[i<4c from the kidneys.^lbumiimriiij^ hsematuria^ These lesions, iire~~inorej? less severe, last for several. days, and then si ( ) w 1 y d i s appea£5t§Li5Sod^^ yalesc_ence. In many__cases they leave behind them traces which last for months and even years, and they then more 6?Tess~aSect tlieEealth of the^ubjects according to the orgajislhaFwere"lrro^ rnosTseiSjirfy-affecteJ^ ' ■ ~ ' In certain cases, in domestic animals such as dogs, and more rarely in man, after recovery from the bite of a viper, total or partial loss of sight, smell, or hearinfj. Via.a been observed. Rru»h-- resuttsrRbwever, are fortunately exceptional. 179 CHAPTER VII. PHYSIOLOGY OF POISONING (contimced). Effects of the Various Venoms on the Different Tissues - — of' the Organism. The physiological effects of the various venoms are very different from those that we have just described, when these toxic substances are introduced into the organism otkerwise than-- subcutaneously. - -Their direct penetration into the blood-stream, whether by the bite of the snake itself or by experimental intravenous injec- tion, always produces immediate results. With the venoms of ViPERiDiE, cpagulatioii ofjUie^ blood and^^^nsequently, death are almost install ta.Tip.mis. With the venoms of Colubrid^, which, on the contrary, destroy the coaoulability of the blood, the toxic effects are less rapid, but after the lapse of only a few minutes asphyxia ensues and the death-struggle is very short. » Absorption by the serous membranes is slower, but is never- theless effected much more quickly than when it takes place in the subcutaneous cellular tissue.— When cobra-venom is injected into the peritoneal cavity of a rabbit or a guinea-pig, the local effects upon the serous membrane are almost nil. No leucocytic exudation is observed ; death supervenes before this has had time to take place. The venoms of ViPERiDiE, on the contrary, produce, directly after their introduction into the peritoneum, an enormous afflux of sanguinolent serosity ; the capillary vessels of the serous membrane, immediately becomingJisIi55idIlaJlow bloodT to filter through their walls^ and the animal succujxibg 180 VENOMS after a few minutes, or a few hours, according to the dose injectedj^ withThe^eritoneum full of blood. — When deposited upon the mucous membranes of the eye, vagina, or urethra, all venoms, those of Colubiiid.?e like those of ViPiiRiDiE — but the latter with greater intensity — cause very acute inflam- mation, comparable to that produced by jeguintyj the capillaries "l5ecome distendecl, allow leucocytes to exude en masse, and, asfor_ 'mstance'^upon the eye of the rabbit, a parulent_ophthalmia soon eslabtisBes itself. Certain species oiSepeclon (Colubrid^), common on the West Coast of Africa, especially in Senegambia and in the hinterland of Dahomey, and to which the name Spitting Snakes has been given, possess the faculty of projecting little drops of venom to a distance by forcibly expelling the air from their lungs, and the natives assert that this venom, when it bappens to come into contact with the eyes, causes blindness. This is true to a certain extent, in so far as it produces attacks of purulent ophthalmia which are often serious ; bat these attacks, like those provoked experimentally in animals, can be cured in a few days when properly treated, When absorbed by the digestive tract, the venoms of Colu- BRiD.E often produce no ill-effects. It is otherwise with those of ViPERiD^. The venom of Laohesis, for example, if adminis- tered in sufficient doses, sets up acute inflammation of the gastric mucous membrane, and the animals speedily succumb with attacks of gastro-intestinal haemorrhage, even before it has been possible for the toxic effects upon the nerve-cells to become apparent. These facts explain the contradictions that are to be found in the works of different investigators upon this subject. It is affirmed by some writers that venom can be swallowed without danger, and they even advise the sucking of venomous wounds in order to hinder its absorption. Others, including Sir Joseph Fayrer, Eichards, and Weir Mitchell, have killed pigeons and fowls by making them ingest venom o£ Vipera russellii, or Crotalus, THE PHYSIOLOGY OF POISONING 181 C. J. Martin, in experimenting upon rats with the venom of Pseudechis (Colubrid.i:), has succeeded in keeping these animals ahve for a whole week by providing them every day with a ration of bread and milk mixed with a dose of venom one hundred times greater than the lethal dose for a subcutaneous injection. This innocuousness of the venoms of CoLUBuiDiE, which I have frequently been able to establish by causing them 'to be ingested by different animals, is explained by the fact that the pancreatic juice and the ptyalin of the saliva very rapidly modify the proteic sub- stances to which these venoms owe their toxicity, so that this disappears. No trace of them is found in the faeces. The glandular secretions of persons bitten by venomous snakes, and those of animals inoculated with doses of venom calculated to kill only after a few hours, are not infrequently found to be toxic. In the case of the urine in particular this has been shown to be so. Observations have also been recorded by C. Francis^ and Sir Joseph Fayrer with reference to the passage of venom through the mammary gland. In the year 1893 a poor Mussulman woman died at Madras from the bite of a Cobra. She was nursing her child at the time, and the latter succumbed in its turn a few hours later, with all the symptoms of poisoning, although it had not'itself been bitten, and had been suckled by its mother only once since the bite. The histological lesions produced by snake poisoning have been particularly well studied by Hindale,^ Karlinski,^ Nowak,'* Louis Vaillant-Hovius,' and Zeliony.^ ' Indian Annals, July, 1868. ■ Medical News, Philadelphia, 1884. " Zur Pathologic des Schlangenbisses," Forschungen der Medicin, Berlin, 1890. * Annales de VInstitiit Pasteur, t. xii., 1898, p. 369. ^ These Bordeaux, 1902. * Virchow's Archivfiir Pathologic, Anatomie, inid Physiologic, Baud 179, 1905. Venoms (1) Action upon the Livee. Whether we are dealing with the venoms of Viperid/E or CoLUBRiD^, the anatomo-pathological processes are ahke, and the changes produced are more or less profound, according to the degree or the slowness of the intoxication. The liver is more affected than any other organ. In cases in which death has quickly followed the injection of the venom, the protoplasm of the cells is merely cloudy, or granular, and the granulations readily take a stain in their periphery, though the interior remains uncoloured. If, on the contrary, the animal has survived for some hours, the protoplasm becomes condensed in certain parts of the cell, leaving vacuoles, the hmits of which are not well defined. A portion of the cellular protoplasm is necrosed and destroyed. In these cases the nuclei have already undergone a change ; although their contours may be well defined, we discover in their interior only a very little chromatin in the form of small granulations, and the nuclear fluid takes a feeble stain with basic colours, since it contains a little chromatin in solution. When the protoplasm of the hepatic cells has suffered more pronounced lesions, the changes in the nuclei are also more marked ; the quantity of nuclear chromatin diminishes and slowly loses its property of taking stains, in proportion as the protoplasm of the hepatic cells undergoes necrosis ; finally, in the hepatic cell, there remains nothing more than a small quantity of granular proto- plasm without a nucleus (Nowak). In certain cases we find extensive areas of fatty degeneration, or small foci in which the hepatic tissue is absolutely destroyed. In the case of the dog it may even happen that the microscopic structure of the parenchyma has entirely disappeared. The arrange- ment of the hepatic cells in lobules can no longer be distinguished ; the trabeculae are ruptured and broken asunder, and we find nothing more than a confused agglomeration of cells floating in the extra- vasated blood. THE PHYSIOLOGY OF POISONING 183 In animals which have hved for a long time after being poisoned, lesions of the bile-ducts are also found. The epithelial cells have undergone fatty degeneration, or else, in the case of small animals, the ducts appear infiltrated with small mononuclear cells, which penetrate between the epithehal cells of the canaliculi. Sometimes also the latter cells are distended, and enclose large vacuoles. Venom thus produces in the liver lesions of fatty degeneration, or necrosis, and an infiltration of the bile-ducts by lymphatic cells. (2) Action upon the Kidney. The changes in the kidney are also very extensive. The three portions of the glomerulus -often exhibit lesions; the vessels of the tuft show ectasia ; their walls are sometimes ruptured, and the blood is extravasated into the capsular cavity. The latter is filled with a granular exudation, which varies in amount with the slowness of the intoxication. The epithehal lining of Bowman's capsule is swollen ; the nucleus stains badly (Yaillant-Hovius). In the tubuli contorti the lesions in the cells greatly resemble those seen in the liver. Granulations and vacuoles appear, and the nucleus becomes diffuse. The lumens of the tubules are tilled with necrosed cells, aud the branches of Henle are found to be similarly obliterated. In the straight tubes and in the collecting tubes the epithelium is sometimes detached in its entirety. Some of these canals are obliterated by granular cylinders or by accumulations of epithelial cells. The vessels met with in the parenchyma of the kidney are always greatly distended, and sometimes they are torn, whence there results the formation of small foci of interstitial hsemorrhacre. In many cases the extravasated blood also destroys the parenchyma. (3) Action upon the Spleen, Heart, and Lungs. In the spleen, Nowi \ merely found a little fatty degeneration, and only in cases in which the lesions in the liver and kidneys 181 VENOMS were very far advanced. The same applies to the muscular fibres of the heart. This organ exhibits, above all, haemorrhagic infiltra- tions in its peripheral portion, rarely in its substance. The lungs are the seat of more important lesions. We find in them a multitude of little infarcts. Around these the capillary vessels are extremely dilated, and the pulmonary vesicles bave become very small. All these lesions of the visceral organs strangely resemble those observed in the case of individuals who have died from yellow fever. This observation has been made by several scientists, among others by Sanarelli, and it is this perhaps that has suggested to some (Dyer, of St. Louis, E. Bettencourt, of Suo-Paulo^) the idea of treating — without much success, however — yellow fever by the antitoxin of venom. (4) Action upon the Striated Muscles. The changes in the striated muscles in places at which venom has been injected do not present any specific character. The muscular fibres already become necrosed half an hour after the injection ; the diseased tissue becomes permeated with an albumin- ous mass rich in fibrin, and the blood is extravasated. A few hours later we observe, between the bundles of degenerate muscle fibres, polymorphous leucocytes. The number of these latter con- stantly increases, and attains its maximum after one or two days. The muscular nuclei become distorted, appear long or angular, and assume the aspect of myoblasts (sarcoblastic muscle cells). In the protoplasm of the myoblasts we frequently find particles of broken- down muscle, and globules of fat. All these changes resemble those observed as the result of the action of a host of other muscle poisons, especially the irritant or caustic chemical substances. ^ Societe de Jledecine et de Chirurgie de Sao Paulo (Brazil), June 15, 1904. THE PHYSIOLOGY OF POISONING 185 (5) Action upon the Neevous Centres. It is extremely difficult to determine with any degree of pre- cision the nature of the lesions produced by venoms in the nervous system. The intensity of these lesions depends in the first place upon the length of time that has elapsed between the introduction of the venom into the organism and death. It depends, secondarily, in a large measure, upon the origin of the venom. That of the YiPERiDiE acts almost exclusively upon the blood by coagulation, and exhibits only a very slight degree of toxicity as regards the nerve-cell. That of the Colubeid^, on the contrary, produces manifest changes in the chromatic substance. Nissl's bodies are coixipletely disintegrated, and transformed into a granular mass. In the majority of the stichochromes neither the form of the bodies nor even the reticulum is distinguishable. The nuclei are opaque, the nucleoli swollen and broken up. The dendrites often become irregular and contracted (Ewing and Bailey,^ G-. Lamb^). It was found by Bailey that the majority of the cells of the anterior cornua of the medulla are normal, but that a small number of them exhibit indications of acute granular degeneration ; a few cells were found to have lost almost all their chromatic substance. From the physiological point of view it is perfectly clear that Cobra-venom especially affects the bulbar centres, and particularly the nuclei of origin of the pneumogastric nerve. We observe m the first instance the gradual suppression of the functions vested in the nerve-cells that are found in connection with the vagus nerve, the spinal accessory, and the hypoglossal. Later on the excitability of the nerve-endings in the muscles is found to have been destroyed, and this action presents great similarity to that of curare. The venoms of Vipeeid^, when injected in very weak doses, exercise a paralysing action upon the reflex excitabihty of the ' Medical liecord, September 15, 1900. 2 Lancet, January 2, August 20, October 22, 1904, and September 23, 1905. 186 VHNOMS medulla. But it is open to question whether these effects are not exckisively due to the lesions of the blood, which are here all- predominant; for no histological modification is observed in the cells of the central nervous system. I have made a number of experiments with a view to discover- mg whether the cerebral, bulbar, or medullary substance of animals susceptible to the action of Cobra-venom (rabbit, guinea-pig, fowl) possesses the property of fixi7ig this venom as it fixes the toxin of tetanus (Wassermann and Takaki). I found that, on pounding up a little of the pulp of the cerebral hemispheres or bulb with doses of venom lethal in two hours for the control animals, the injection of the mixture, well washed and centrifuged in order to free it from all excess of non-fixed venom, always caused death, but with a retardation of from four to ten Jiours. We see, therefore, that partial fixation of the venom upon the nervous elements really takes place, but we cannot conclude from this that these elements exercise an antitoxic function, any more than in the case of tetanus, for animals that receive cerebral emulsions in one thigh and the dose of venom lethal in two hours in the other thigh, succumb at the same time as the controls. Major Eogers has made similar experiments with the venom of Enhydrma (Hydeophiid^), and has obtained the same result on employing the cerebral hemispheres of the pigeon.^ Plexner and Noguchi," on their part, have compared, by aid of the method of intracerebral injections, the toxicity of the venom of Crotalus with that of the venom of the Cobra. On employing Cobra-venom heated to 75° C, they found that the convulsive and paralytic effects were immediate, contrary to what takes place after subcutaneous or intraperitoneal injections, but that the dose of venom necessary to produce death was the same ' Proceedivgs of the Boy al Society, vol. Ixxi., 1903. - " The Constitution of Snake-venom and Snake-sera," University of Penn- sylvania Medical Bulletin, vol. xv., 1902, p. 345. fiiE PHYSIOLOGY OF POISONING 187 (0-1 milligramme for the guinea-pig) as when the injection is made in the peritoneum or beneath the skin. With the venom of Crotcdus heated for half an hour at 75° C, which contains but very Httle neurotoxin and has lost all its hemorrhagic properties, 0-5 miUigramme introduced directly into the brain of the guinea-pig only produces transitory and non-lethal effects; while, if fresh venom be employed, 0-05 milligramme is sufficient to cause death in' three hours, with severe hsemorrhagic lesions. Now this dose is twenty times smaller than the minimal lethal dose for a subcutaneous injection. It is evident that the harmful matter, in the particular case of Grotalus-Yenom, is not the neurotoxin, but an altogether different substance, termed by Flexner and Noguchi hcemorrhagin, which acts upon the elements of the blood and upon the endothehum of the blood-vessels. We shall meet with this substance again in almost all Vipeeine venoms, and shall study it further on. 188 CHAPTER VIIL PHYSIOLOGY OF POISONING {continued). Action of Venoms on the Blood. On making an autopsy of an animal which has succumbed to intoxication by snake-venom, we find that the blood in the heart and large vessels is sometimes coagulated into a mass, sometimes entirely fluid, and that, in certain cases, it is as black as prune- juice, while in others it is of a fine transparent red colour. These differences in the effects of venom upon the blood are due to the fact that the various venoms contain in variable pro- portions, besides the neurotoxic substance which represents the true venomous toxin, other substances which act, some upon the plasmasia or fibrin-ferment, or upon the fibrin, others upon the red corpuscles, others on the leucocytes, and others again on the endothelium of the blood-vessels. A. — Effects of Venom on the Coagulation of the Blood. It was observed long ago by Fontana^ that after viper-bites the blood remains fluid, and Brainard^ on the contraiy, pointed out that, in the case of animals that succumb very rapidly after having been bitten by a Ci-otalus, the blood was always found coagulated into a mass, while, when a certain interval of time had elapsed since the bite, it remained fluid. Weir Mitchell^ 1 Fontana, " On Poisons," translated by J. Skinner : London, 1787. ^ Smithsonian Beports, 1854. ' Smithsonian Contributions to Knoivledge, 1860. [■ THE PHYSIOLOGY OF POISONING 189 explained these differences by the hypothesis that, in cases of rapid death, the blood had not had time to become modified by the venom. Later on it was found by Sir Joseph Fayrer, and subsequently by Halford,' in Melbourne, C. J. Martin,^ in Sydney, G. Lamb,^ in Bombay, and recently by Noc, in my laboratory, that the venoms of ColubriD-E, especially those of Naja tripibdians and Australian species of this family, always leave the blood fluid after death, while the venoms of Viperid^, on the contrary, are usually coagulant. On the other hand, it was observed by ' Phisalix,"^ and at an earlier date by Mosso, of Turin, that the venom of Vipera hems causes the blood of the dog to lose its coagulability, while, on the contrary, the same venom is actively coagulant as regards the blood of the rabbit. How are these differences of action to be explained? It was found by Delezenne,^ who made an excellent study of the phenomena following the injection of peptone, extracts of organs, and other anti-coagulant substances into the organism, that those of these substances that render the blood non-coagulable always dissolve the leucocytes, and thus set at liberty two antagonistic bodies which they contain. One of these substances is coagulant and is found retained by the liver, while the other remains in solution in the plasma, and keeps the blood fluid after issuing from the vessels. Now, certain extracts of organs, ricin, abrin and certain venoms in weak doses, retard coagulation, while in large doses, on the contrary, they produce partial or general intravascular clotting. It is believed by Delezenne that the explanation of this ' Medical Times and Gazette, vol. ii., 187B. - " On the Physiological Action of the 'N'enom of the Australian Black Snake," Proceedings of the Boyal Society of New Soutli Wcdes, July, 1895. ^ Indian Medical Gazette, Decembei', 1901. Comxites rendus de la Societe de Bioloijie, November 4, 1899, s Ibid., October 28, 1E99, 190 VENOMS phenomenon may be that the doses, which are, weak but sufficient to produce the disintegration of the leucocytes, injure the red corpuscle in only a slight degree, while the stronger doses are equally destructive to the two kinds of blood corpuscles. It follows that we must understand that there are two phases in the action of venoms : one negative, when the dose absorbed does not injure the leucocytes ; the oi\iet positive, when the leuco- cytes are destroyed. If the blood of the dog remains non-coagulable when mixed with doses of venom which, on the contrary, are actively coagulant for the blood of the rabbit, the reason would be that the leucocytes of these animals are not equally resistant to venom. This conception, however, does not conform to the facts that I have myself observed. I have always found tbat viper-venom, mixed with citrate- or oxalate-plasma of the dog, rabbit, or horse, coagulates these various plasmas when the venom is in weak doses, while with strong doses coagulation is not produced. To be quite accurate, it should be stated that the quantity of venom necessary to render the plasma of the dog, or of the horse, non-coagulable is less than that which must be employed in the case of the plasma of the rabbit. I have caused Noc to take up anew the study of this question in my laboratory, with venoms of nine different origins, and I here give a resume of the results of his researches.^ I. Coagulant Venoms. The venoms of Viperid^ studied range themselves as follows according to their coagulant power : — Crotalin^ : Lachesis lanceolatus (Fer-de-lance, Martinique). Lachesis neuwiedii (Urutu, Brazil). Lachesis mutus (Bushmaster, or Surucucu, Brazil). Lachesis flavoviridis (Japan). ViPERiNiE : Vipera russellii (Daboia, India). ' Annates de VInstitut Pasteur, June, 1904, THE PHYSIOLOGY OF POISONING 191 The venoms of Ancistrodon contortrix and A. piscivorus (Cro- TALiN^) proved entirely inactive. No CoLUBRiNB venom exhibited coagulant pov^er, whatever the dose employed. There is, therefore, a very decided difference between venoms of divers origins as regards their effects upon the coagulation of the blood. Noc has determined more especially the coagulant action of the venom of Lachesis lanceolatus (Per-de-lance of Martinique) upon 1 per cent, citrate-plasmas, 1 per cent, oxalate-plasmas, 4 per cent, chloridate-plasmas, and upon blood rendered non-coagulable by extract of leeches' heads. He found that, while weak doses of venom (1 milligramme per cubic centimetre of horse- or rabbit- plasma) produce coagulation in a- few minutes in the citrate- plasmas, chloridate-plasmas, or those treated with extract of leeches, the doses of the same venom greater than 4 milligrammes on the contrary suppress the coagulability of these plasmas, even when there be added to them doses of chloride of calcium (for the citrate- and oxalate-plasmas), or of distilled water (for the chlori- date-plasma), or of fibrin-ferment (for the plasma treated with leech-extract) sufficient to cause rapid coagulation in the control tubes that do not contain venom. Noc also observed that the venom of the same species of snake (Lachesis lanceolatus), when heated to 75° C, entirely loses its coagulant properties ; and that, with a temperature of 58^ C, its coagulant power already commences to diminish. When heated for thirty minutes at a temperature of 65° C, a dose of 1 milli- gramme does not coagulate more than 1 c.c. of citrate-plasma in one hour. G. Lamb has likewise found that the venom of Vipera russellii loses its coagulant power when heated to 75 C. The coagulant substance in these venoms is precipitable by alcohol at the same time as the neurotoxin and other active sub- stances. The precipitate, when dissolved again in physiological water, preserves all the properties of the original solution, 192 VENOMS Antivenomous anticoliibrine senim, that is to say, that fur- nished by horses vaccinated against the venoms of the Cobra and the Krait, does not prevent coagulation by coagulant venoms. This need not surprise us, since the coagulant substances in venoms are destroyed by heating, and the animals vaccinated in order to obtain antitoxic serum are usually inoculated exclusively with heated venoms. It is easy, however, to obtain active serums specific against the coagulant venoms ; it is sufficient to treat these animals b}' inoculation with progressively increasing doses of the same venoms nnheated. I have had no difficulty in achieving this result with small laboratory animals (guinea-pigs and rabbits) and also with the horse, but I have never had at my disposal a sufficient amount of the venoms of Lachesis or Vipera russellii to undertake with them the regular acquisition of large quantities of horse-serum, at once antineurotoxic and anticoagulant. The preparation of such a serum, nevertheless, presents much interest for certain countries, such as Burma, where the Daboia {Vipera russellii) is almost as common as the Cobra, and Brazil, where nearly all the casualties due to venomous snakes are produced by Lachesis} II. — Anticoagulant Venoms. Contrary to what is observed with the venoms of Viperid.e in general, all the venoms of Colubrid^ and, as exceptions to the rule, the venoms of some North American Crotalin^ {Ancistrodon contortrix and A. piscivorus) suppress the coagulability of the blood in vivo and in vitro. It is, however, important to observe that, in vivo, the blood remains fluid after death only if the dose of venom absorbed has been sufficient. In vitro this phenomenon is easier to study, and has been the subject of several important memoirs. ' At the Serum-therapic Laboratory of Sao Paulo (Brazil), Dr. Vital, Brazil, is at the present time preparing serum specific against Lachesis-venom, THE PHYSIOLOGY OF POISONTNG 193 Halford,' Sir Joseph' Fayrer,- C. J. Martin,^ Delezenne,' Phisalix;'^ and lastly Noc," have shown that the venoms of CoLUBRiDiE exert a manifestly anticoagulant action upon citrate-, chloridate-, or oxalate- plasmas, and also upon blood mixed with venom on issuing from the vessels. On adding 1 milligramme of Cobra-, Bangarus-, Australian Pseudechis-, or Ancistroclon-venom. to 1 c.c. of citrate-, oxalate-, or chloridate-plasma, and supplementing the mixture, after varying periods of contact, with a quantity of chloride of calcium (for the citrate- or oxalate-plasmas), or distilled water (for the saline plasma) sufficient to produce coagulation in a few minutes in the control tubes without venom, we find that coagulation no longer takes place after one hour in the tubes containing Cobra- or Bungarus-yrenom., and after ten minutes in those that contain the venom of Ancistroclon. In doses less than 1 milligramme for 1 c.c. of plasma, these venoms by themselves never produce coagulation as do those of Lachesis or Vipera russeUii. They are thus sharply differentiated in this respect. If fresh blood issuing from the arteries of an animal be received in a vessel containing a sufficient quantity of CoLUBEiNB-venom (that of the Cobra for example), and steps be immediately taken to ensm'e the pe^rfect mixture of the venom and the blood, we find that the latter has entirely lost its coagulability, just as though it had been mixed with peptone or extract of leeches' heads. Again, if a mixture be made in vitro of coagulant venoms, such ' Medical Times and Gazette, vol. ii., 1873. " The Thanatophidia of India." Churchill, London, 1872. ' " On the Physiological Action of the Venom of the Australian Black Snake," Proceedintjs of the Boyal Society of New South Wales, July 3, 1895. ■' Archives hiologiqiies, 1897 and 1898 ; Comj^tes rendtts de la Societe do Bio- lorjie, October 28, 1899. ^ Comptes rendtts de la Societe de Biologic, October 28, 1899 ; November 4, 1899 ; July 26, 1902. " Annales do VInsiitut Pasteur, June, 190-1, 13 isu VENOMS as that of the Lachesis, with uiiLicoaf^ulaut venoms such as that of the Cobra or of Ancistrodon, it is found that these mixtures, when properly effected, become neutral, so that the respective effects of the component venoms are entirely destroyed. Assuming, for instance, that 1 milhgramme of Lachesis-venom coagulates in two minutes 1 c.c. of 1 per cent, citrate rabbit-plasma, if we add to the plasma firstly 1 milligramme of Ancistrodon-, or 1 milligramme of Co&/-a-venom, and then 1 milligramme of Lachesis-venom, the plasma remains non-coagulated, yet coagulates perfectly on the subsequent addition of 1 c.c. of a | per cent, solution of chloride of calcium. There is, therefore, a real antagonism between the actively coagulant substance contained in certain Viperine venoms and the anticoagulant substance comprised in the venoms of certain other ViPEBiD^ {Ancistrodon), belonging to the subfamily Cko- TALiN^, and in those of all the Colubrid^. The conclusion to be deduced from the foregoing facts is that the venoms of Colubrid^ and those of certain Viperid^ are decidedly anticoagulant, while the majority of the venoms of ViPERiDiE, on the contrary, possess strong coagulant properties, even when mixed with blood in infinitesimal doses. The question therefore arises why these coagulant Viperine venoms suppress the coagulabihty of the blood when mixed with it in vitro in strong doses (for example, in doses beginning from 4 milligrammes of Z/ac/ims-venom, or 7 milligrammes of the venom of Viper a russellii for 1 c.c. of 1 per cent, citrate rabbit-plasma). The explanation of this apparently contradictory phenomenon is furnished by the intense proteolysis that these Viperine venoms exert upon fibrin, in solution or coagulated. This proteolysis actually manifests itself with weak coagulant doses, for the compact clots formed at the outset soon become soft and then dissolve, like a cube of egg-albumen in an experiment in artificial digestion by trypsin. We shall revert to the subject later on. THE PHYSIOLOGY OF POISONING 193 III.— Mechanism of the Anticoagulant Action of Venoms on THE Blood. The anticoagulant action of the venoms of CoLUBRiDiE and of Ancistrodon xnpon the blood appears to take effect in the first place upon the fibrin-ferment, and afterwards upon the fibrin by proteo- lysis. The action on the fibrin-ferment seems manifest when we experiment with anticoagulant venoms which are feebly proteolytic, like the venom of the Cobra. I have already stated that a mixture of fresh blood with a suffi- cient dose of Co5;-a-venom is non-coagulable, as though the blood on issuing from the animal had been mixed with peptone or leech- extract. But, while blood when peptonised or mixed with leech- extract coagulates readily on the subsequent addition of fibrin- ferment, blood mixed with venom remains positively non-coagulable. It is the same with citrate- or oxalate-plasmas, which no longer coagulate when chloride of calcium is added to them, and with 4 per cent, saline plasma on the addition of distilled water. The anticoagulant substance in the venoms of Colubrid.^; and Ancistrodon is precipitable by alcohol, hke the coagulant substance m the venoms of ViPERiDiE and like the neurotoxins, from which it IS difficult to separate them. The separation can nevertheless be effected by the aid of heat, if we make use of certain venoms that are particularly resistant to high temperatures, such as those of the Cobra or the Krait. These latter venoms, when heated for one hour at 70° C, cease to be anticoagulant, and preserve their toxicity unimpaired. It is, however, impossible to suppress the toxicity without at the same time destroying the anticoagulant substance. Antivenomous serum completely protects citrate- or chloridate- plasmas against the anticoagulant action of venoms. It is sufficient to mix ^ c.c. of 4 per cent, saline antivenomous serum with 1 c.c. of 4 per cent, saline plasma to ensure that the subse- quent addition of 1 milligramme of Cobra-yenom to this mixture remains without effect upon the coagulability of the latter. If, 196 VENOMS after a contact of two hours or more, 2 c.c. of distilled water be added, coagulation is produced just as in saline plasma without venom. B. — Effects of Venom upon the red Corpuscles. (1) Hcemolysis. — The haemolytic properties of venoms, that is to sa)', their faculty of dissolving the red corpuscles, have been the subject of very important researches on the part of a number of investigators during the last few years (W. Stephens,^ Flexner and Noguchi,^ Calmette,^ Phisalix,^ Preston Kyes and Hans Sachs,"^ Noc«). The different venoms are all haemolytic, but in very variable doses. It is possible to make a very precise comparative study of them from this special point of view by taking as a base for each venom, as was done by Noc, the unital dose of 1 milligramme (or one-tenth of a cubic centimetre of a 1 per cent, solution freshly prepared and not filtered, the filtration through porcelain retaining an appreciable part of the active substance), and noting the time strictly necessary for this dose of 1 milligramme to dissolve com- pletely, in vitro, 1 c.c. of a 5 per cent, dilution of red corpuscles of the horse in physiological saline solution. It is very important, before allowing the venom to act on the red corpuscles, to first wash the latter by means of several suc- cessive centrifugings with 8 per 1,000 physiological saline solution. It is also better to choose the corpuscles of the horse in preference to those of other species of animals, since they exhibit • Journal of Pathology and Bacteriologi/, 1899-1900. 2 Journal of Experimental Medicine, March 17, 1902 ; TJniversiiy of Penn- sylvania Medical Bulletin, November, 1902. 3 ComplcH rendus dc V Academic dcs Sciences, June 16, 1902. " Comities rendus de la Socictc de Biologic, No. 27, 1902. ■• Berliner klinische Wochenschrift, Nos, 88, 89, 1902 ; Nos. 2-4, 1908 ; Nos. 42-43, 1903. « Annalen dc VInstitut Paateur, 1904, p. 387. THE ri-IYSIOLOGY OF POISONING 197 a nearly constant mean sensitivity. The corpuscles of the ox, goat, sheep, and rabbit are less sensitive. Those of man, the guinea-pig, and the rat, on the contrary, are more so. On experimenting with washed corpuscles, it is found that venom alone is incapable of dissolving them. In order that dis- solution may take place, we are obliged to add to the mixture either a small quantity of normal horse-serum, preferably heated, and, consequently, deprived of alexin (Calmette), or i c.c. of a 1 in 10,000 solution of lecithin in physiological saline water (P. Kyes). Venom, therefore, is capable of hsemolysing red corpuscles only when it is quickened, either by heated normal serum, or by lecithin. The solution of lecithin employed for this purpose should be pre- pared by dissolving 1 gramme of lecithin in 100 grammes of pure methylic alcohol. Taking 1 c.c. of this dilution we add it to 9 c.c. of 8 in 1,000 saline- solution, and make a second dilution of 1 c.c. of the foregoing mixture in 9 c.c. of saline water. This latter dilution of 1 in 10,000 is utilised as the reagent. Let us now see how the serum or lecithin acts. It has been shown by P. Kyes that with either of these substances the mecha- nism of the hEBmolytic action is the same, for the serum quickens the venom only through the agency of the free lecithin it contains. The lecithin takes part in the reaction by combining with the venom to form a haemolysing lecithide more resistant to heat than its two components, for it may be heated for several hours at a temperature of 100° C, without the loss of any of its properties. When venom is brought into contact with certain kinds of highly sensitive red corpuscles, those of the rat for example, these corpuscles, although washed and freed from serum, may undergo haemolysis. This result is due to the fact that these corpuscles contain sufficient quantities of lecithin, which becomes liberated from their protoplasm and, uniting with the venom, constitutes the active lecithide. It was already known that lecithin is capable of combining with various albuminoid matters and with sugars to form lecithides. 198 VENOMS We must not, therefore, be surprised to find that such a combination may take place with the proteic substances in venom. The com- bination in this case is a truly chemical one. Lecithin in its natural state, or that which is normally found in serums which quicken venom, such as horse-serum, even when heated to 65° C, therefore plays the part of comjjlement according to Ehrlich's theory, or that of alexin according to the theory of Bordet, while venom itself would be an amboceptor or sensitiser. This is not, however, the way in which the phenomenon should be understood, for it is impossible to admit the identification of heated serum or lecithin with the complementary substances or alexins, seeing that the essential characteristic of the latter is that they are intolerant of heat and become entirely inactive on being raised to a temperature of 58" C, or even by simply being kept for a few days exposed to the air and hght. We must therefore suppose, with P. Kyes and H. Sachs, that the red corpuscles them- selves contain substances capable of playing the part of comple- ments iendo-coni'plements) , and that it is with these that the venom combines when quickened by the presence of lecithin or heated serum, the latter only acting because it contains free lecithin. All substances that contain lecithin, such as bile, hot milk, or cephalin, are capable of exerting the same quickening action, but do not themselves possess any inherent hsemolytic power. Cliolesterin, on the contrary, represents a kind of antidote to lecithin, as also to normal serums. It prevents haemolysis of the red corpuscles in a mixture of washed corpuscles and venom, yet it does not in any way modify the properties of true alexins or complements. Moreover, no correlation exists hetween.lecitJiides and the neuro- toxin in venoms. The combmation lecithin + venom possesses Jmmo- lytic action, but is in no way neurotoxic. Conversel}'.. venom can be freed from its groups of molecules combinable with lecithin, and remain neurotoxic. Lecitliide is insoluble in ether and acetone, but soluble in THE PHYSIOLOGY OF POISONING 199 chloroform, alcohol, toluene, and water. Its properties are there- fore entirely distinct from those of its two components. It pre- cipitates slowly from its aqueous solutions, without losing its hsemolytic power; it does not show &^^^re^-reaction ; it dissolves with equal readiness the red corpuscles of all species of animals, and its effects, like those of venom, are impeded by cholesterin. Kyes has succeeded in obtaining lecithides with all the hsemo- lytic venoms that he was able to study: thus he has prepared lecithides from Lachesis lanceolatus, Naja haje, Bungarus, Lachesis flavoviriclis, and Crotcdufi. It is therefore probable that the lecithino- phile group exists in all venoms, even when these differ as regards their other properties. A wide range of difference is exhibited by the various venoms, as regards their hgemolysing power in the presence of normal heated serum or lecithin. The venom of Naja and that of Bungarus are the most active. The action of the venoms of ViPERiDiE, and especially of those of Grotaliis, is very weak. For example, while 1 milligramme of Golra-venom dissolves in from five to ten minutes 1 c.c. of a 5 per cent, dilution of red corpuscles in the presence of lecithin or normal heated serum, the same dose of the venom of Vipera russelUi takes thirty minutes to effect the dissolution, and . the venom of Lachesis lanceolatus takes three hours. P. Kyes and H. Sachs have discovered the apparently para- doxical fact that, if to the red corpuscles of certain species of animals CoZ)?-a-venom be added in increasing doses, haemolysis augments up to a certain point, beyond which the destruction of the corpuscles shows progressive diminution. In a large dose CoZ;?-a-venom no longer produces any effect upon the corpuscles of the horse, for example, even when the venom is added in presence of a great excess of lecithin or heated serum, It would seem, then, that, according to the theory of Ehrlich, under the influence of an exaggerated amount of venom-amboceptor there is produced a deviation on the part of the complement (serum or 200 VENOMS lecithin), and that the latter, instead of fixing itself upon the corpuscles, becomes united with the surplus fraction of the ambo- ceptors, which has remained free in the liquid. Noguchi,! resuming the study of this extremely curious action of strong doses of venom, observed that the red corpuscles of certain species of animals (such as the horse for example), when previously washed and held in suspension in a physiological solution of sea-salt containing 4 per cent, of Cohra-venom, acquire a considerable augumentation of resisting power with regard to various physical and chemical agents. In consequence of this they are no longer hajmolysed by distilled water, ether, or saponin. Nevertheless, acids or alkalies, except ammonia, destroy cor- puscles treated with venom more easily than those in their normal condition. If corpuscles, previously treated with a strong dose of venom, are subjected to repeated washings in physiological saline solution, the special resistance acquired by them in the presence of the venom disappears ; they even become more sensitive to the action of destructive agents, such as water, ethsr, or saponin. The principle contained in venom, to which must be attributed the protective action, is not destroyed by heating to 95° C, although at this temperature (7o6ra-venom becomes partially coagulated. Moreover, the protective substance is contained in the coagulum, while the hcemohjsin remains entirely in the filtrate. The agglutinin of venom, on the other hand, is destroyed at a temperature of 75° C. The protective substance, therefore, can be identified neither with the hsemolysin nor with the agglutinin. It follows that it is impossible to accept the hypothesis of the " deviation of the complement " suggested by Kyes and Sachs to explain the innocuousness of strong doses of venom. Besides, it would be difficult to reconcile this hypothesis with the fact, observed by Noguchi, that venom in a strong dose protects cor- ' Journal of Exp3rim2iifa.l Medicine, 1905, No. 2, pp. 191-222. THE PHYSIOLOGY OF I'OISONING 201 pascles, not only against the action of lecithin (complement), but also against distilled water, ether, &c. Noguchi, seeking more thoroughly to elucidate the mechanism of this protective action, finds that Gohra-venom forms a precipitate with blood-serum, when the latter is relatively poor in salts or when it is diluted with water. It likewise forms a precipitate with the aqueous extract of red corpuscles, and precipitates the globulins, haemoglobin, or globin of the corpuscle, when treated separately. The precipitates are insoluble in water, but dissolve with the assistance of a small quantity of acid or alkali, and also in a great excess of sahne solution. Noguchi supposes that red corpuscles, when treated with strong solutions of venom, are protected against destructive agents on account of the formation by the venom and certain constituents of the corpuscle (chiefly hgemoglobin) of a compound insoluble in water. When this compound is removed by repeated washings in physiological solution, the corpuscles can easily be hsemolysed afresh by the ordinary destructive agents. Venom, none the less, exerts a noxious influence upon the corpuscles in all cases ; but when strong solutions are employed, this effect is masked by the protective action. All kinds of red blood corpuscles are not equally sensitive to the protective action of strong doses of venom. In this respect all degrees are observed in the action of venom. Thus the cor- puscles of the dog are not protected at all by Co6?'a-venom. But it is interesting to observe that this venom in no way precipitates either the aqueous extract of dog's corpuscles, or the haemoglobin, or the globin of this animal. The venom of Crotalus and that of Ancistrodon Hkewise possess protective power, which is, however, less marked than in the case of Coira- venom. Noguchi finally points out that corpuscles treated with venom are not hoemolysed by fluorescent substances such as eosin. They are also refractory to the hsemolysing action of tetanolysin. 202 VENOMS The resistance of tlie hemolysins of venom to lieat (whicli, according to Morgenroth, may extend to heating for thirty minutes at a temperature of 100° C.) explains how it is that the serum of horses immunised by means of venoms heated to 72" C. is distinctly antihasmolysing, and capable of perfectly protecting the red corpuscles m vitro and in vivo. I have been able to prove that the antineurotoxic property of antitoxic serums with regard to the venoms of Colubrid^ is pretty much on a par with their antihtemolysing property, so that it is possible to measure in vitro the antitoxic activity of a serum by estabhshing the degree of its antihremolysing activity. Thus we see that a serum, which is antitoxic and antihajmolytic with respect to the venom of Naja, is likewise antihffimolytic as regards the other Colubrine -venoms, and even certain venoms of ViPERiDiE. Here we have a very important fact, for it enables us to measure in vitro the activity of antivenomous serums. (2) Precipitins of Venoms. — The serum of rabbits treated with increasing doses of Co&ra-venom precipitates the latter in more or less concentrated solution. It has no effect as regards other venoms. On the other hand, the serum of a strongly immunised horse, the antivenomous power of which was pretty considerable, gave no precipitate with Co&ra-venom ; the formation of precipitate is therefore entirely independent of that of antitoxins (G. Lamb).^ (3) Agglutinins of Venoms. — Besides their haemolytic action, it is easy to observe that certain venoms, especially those of ViPERiD^, agglutinate the red corpuscles, and that the substance that produces this agglutination is different from the hsemolysing substance; for it acts rapidly at a temperature of O" C, at wiiich hfemolysin manifests its effects only with extreme slowness. Heating to 75" C. destroys this agglutinant property (Flexner and Noguchi). ^Lancet, April 2, 1904, pp. 91C-921. THE PHYSIOLOGY OF POISONING 203 C. Effects of Venom upon the White Corpuscles : Leucolysin. The white corpuscles themselves do not escape the action of venom. It is possible in vitro to prove this action upon leucocytic exudations obtained, e.g., by injecting sterilised cultures of Bacillus viegatherium into the pleura or peritoneum of the rabbit; After a few hours this exudation is removed by means of capillary tubes, and, on mixing these with weak doses of venom, we see, in the course of a microscopic examination, that the large mononuclear cells are the first to be dissolved, then the polynuclears, and lastly the lymphocytes. The leucolysis is much more intense and more rapid with Cohra-\enom. than with that of Crotahcs (Flexner and Noguchi, Noc). 204 CHAPTER IX. PHYSIOLOGY OF POISONING {continued). PiiOTEOLYTic, Cytolytic, Bacteeiolytic and various Dias- TASic Actions of Venoms : Diastasic and Cellular Action on Venoms. k. — Peoteolytic Action. The proteolytic action of venoms on gelatine, fibrin, and egg- albumen has been studied by Flexner and Noguchi,' Delezeniie,- and subsequently by Noc^ in my laboratory. It was already known that in vivo certain venoms exert a manifestly dissolving action on the endothelium of blood-vessels and on the muscular tissues themselves. Delezenne, on his part, has established the existence in snake- venoms of a liiiiase analogous to the kinase of leucocytes and enterokinase. Venom alone does not attack egg-albumen coagu- lated by heat, but it confers an exceedingly strong digestive power on inert pancreatic juices. Lachesis-venom has been found to be much the richest in kinase. It digests gelatine perfectly, and when this substance has been subjected to its action it is no longer capable of being solidified. Lannoy,* on the other hand, experimenting upon albuminoid 1 " The Constitution of Snake-venoms and Snalce-sera," T'lriversity of Pennsylvartia Medical Bulletin, vol. xv., November, 1902, p. 345. - Comptes renchis tie I' Academic des Sciences, August 11, 1902. ' Annalps de VInsLitut Pasteur, June, 1904. * " Sur Taction proteolytique des venins," Compies rendus de V Academic des Sciences, September, 1902, and These Paris, No. 1,138, 1903. THE PHYSIOLOGY OF POISONING 205 substances (casein, albumins of ox-serum) in solution, has shown that Cobra-venom and that of Vipem disintegrate the albuminoid molecule ; but the latter remains soluble after the addition of formol and is no longer precipitable by acetic acid. The hydro- lysis never leads to the stage of peptone, but only to the forma- tion of albumoses which give biuret-reaction. The action of venoms upon fibrin may be demonstrated in vitro by bringing sufficient quantities of venom, 1 centigramme, for example, into contact with small fragments of non-heated fibrin, derived from blood clots from an ox, rabbit, or birds, and carefully washed. These fragments soon separate from each other, and become dissolved in a space of time which varies according to the venom used. The ViPEEiNE-venoms, especially those of Lachesis and Ancistrodon, are the most active. Viper-venom is much less so, and the venoms of Colubeidjs are the slowest. This proteolytic action of the various venoms corresponds pretty exactly to their coagulant and decoagulant action on rabbit- or horse-plasma, so that, as I have already stated, we must suppose that the property possessed by YiPERiNE-venoms of more or less rapidly dissolving blood which they have caused to coagulate, results from the fact that these venoms contain, in addition to a coagulant substance, another substance which is strongly proteolytic. The latter is destroyed by heating. Lachesis-venom, when heated to 70° C, no longer has any dissolving action on either gelatine or fibrin. Moreover, antivenomous serum furnished by horses vaccinated against heated venoms does not prevent proteo- lysis by non-heated venoms. On the other hand, the serum of animals vaccinated against ViPERiNE-venoms, simply filtered by the Chamberland process and non-heated, affords perfect protec- tion to gelatine and fibrin against the dissolving action of these venoms. 206 VENOMS B. — Cytolytic Action. Simon Flexner and Noouchi' have observed that the venoms of Naja, Ancistrodon, Crotalus, Vipera russellil, and Lachesis Jiavoviridis, contain substances which possess the property of dis- solving a large number of the cells of warm-blooded and cold- blooded animals, and that these cijtolysins are very markedly resistant to high temperatures. They employed for their experiments 5 per cent, emulsions of organs, spermatozoids, or ova in physiological saline solution. The solution of venom at a strength of 1 per cent, was kept in contact with the different kinds of cells for three hours at a temperature of 0° C. ; the liquid was then centrifuged and exatm"ned with the naked eye and under the microscope. The venoms experimented upon dissolved more or less rapidly the parenchymatous cells of the liver, kidney and testicle of the dog, guinea-pig, rabbit, rat and sheep. The most active venoms in this respect were those of Vipera russellii, Ancistrodon and the Cobra; the venom of Crotalus was the least active. With regard to the nerve-cells, spermatozoids and ova of cold-blooded animals (frogs, fish, arthropods, worms, and echino- derms) Co&ra-venom proved to be the most active ; then that of Ancistrodon, and lastly that of Crotalus. These cytolysins are not destroyed by heating for thirty minutes at 85° C. in a damp medium, nor by dry heating for fifty minutes at 100° C. C. — Bacteriolytic Action. If we bring into contact with a 1 per cent, solution of Cohra- venom, rendered aseptic by filtration through porcelain, sensitive micro-organisms, such as the cholera vibrio, or the bacterium of anthrax in a very young non-sporulated culture, or in its • "On the Plurality of Cytolysins in Snake-venom," University of Penn- sylvania Medical Bulletin, vol. xvi., 1908, p. 163. THE FBYSIOLOdY OF POISONING 207 non-spore-producing variety, we find that these microbes are dis- solved by the solution of venom in varying periods of time. On making a direct microscopical examination we see that Koch's vibrios become immovable, then break up into granulations and disappear in the liquid. The bacteriolysis is even more dis- tinct in the case of the bacterium. The enveloping membrane seems to dissolve, and the microbe appears as though composed of a series of granulations placed end to end, which finally disperse and disappear. By my instructions this bacteriolytic property of venom with respect to different species of micro-organisms was studied by Noc. It was especially clearly seen with the non-spore-producing bac- terium of anthrax, the cholera vibrio. Staphylococcus aureus, the bacillus of diphtheria, and B. subtilis in a young culture ; it is less distinct with B. pestis, B. coU, and B. typhi, is almost nil with the pyocyanic bacillus and B. prodigiosus, and nil with B. tuberculosis. Investigations have likewise been made by Noc, and subse- quently by Goebel,^ in order to determine whether cobra-venom dissolves Trypanosomes. These hsematozoa are more resistant than bacteria, but they nevertheless end by being dissolved after twenty to thirty minutes' contact in the 1 per cent, solution. The bacteriolytic substance in venom is distinct from that which produces proteolysis, for the latter is destroyed at 80° C, while the former only disappears with a temperature of and beyond 85° C. maintained for half an hour. It is likewise distinct from the hsemolysin, for this resists temperatures considerably higher than 85° C. Moreover, venom which has dissolved microbes until the saturation point has been reached, is found to have preserved in its entirety its hfemolytic power upon the red corpuscles of the horse. Neither does it act upon the microbes owing to the presence of a cytase or alexin. The well-known characteristics of alexins are not met with here— destruction at 55° to 56° C, sensitivity to light, rapid alteration at ordinary temperatures, &c. ' Ann. Soc. Med. de Gand, 1905, fasc. 3. 208 VENOMS We cannot, again, compare the bacteriolytic action of venom to that oE rat-serum, which dissolves B. anthracis by aid of a substance distinct from vibrionicide alexin. According to the researches of Malvoz and Y. Pirenne, the lysin of rat-serum appears to be a basic substance, the neutralisation of which destroys its activity. Now Cubra-weuom in a very active solution is perfectly neutral to sensi- tive litmus papers, while these are turned blue by rat-serum. Moreover, venom acts not only upon microbes of the same kind, but also on very different species which are not affected by rat- serum, especially upon B. pestis, for which, on the contrary, this serum, when fresh, proves a favourable culture medium. The bacteriolytic power of Co6ra-venom therefore constitutes a special property of venom. "In their work on the cytolysins of venom, S. Flexner and Nognchi have shown that animal cells, when heated to 55° C. and rendered inactive, do not undergo complete dissolution under the influence of venoms which destroy the fresh cells. The authors in question infer the existence of cellular receptors (endo-comple- ments, according to the theory of Ehrlich), which fix the ambo- ceptors of venom. Pursuing the same order of ideas, I have observed that bacteria killed by heating for one hour at 60° C. do not undergo total disintegration as do living bacteria. But^ while Flexner and Noguchi infer the plurahty of the cytolysiiis in venom for different animal cells, I have not been able to prove the same thing with regard to the bacteriolysin ; venom saturated with cholera vibrios to such an extent that vibrios added at repeated intervals are no longer dissolved, is incapable of dissolving another highly sensitive species of microbe, such as the asporogenous bac- terium, and vice versa. Besides, it would be difficult to understand the existence in venom of cytolysins specific for a whole series of species of micro-organisms" (Noc).^ Antivenomous serum, in a dose of 0-01 or 0-05 c.c, neu- tralizes the bacteriolytic action of 1 milligramme of Cohra-\&nom, ' Annalen tic I'Institut Fabtcur, April, 1905. THE PHYSIOLOGY OF POISONING 209 while normal serum heated, even in larger doses, is without eJi'ect. The lysin and the anti venomous serum appear also to enter into stable combination; by heating to 80° C, after dilution of the mixture neutral autivenomous serum + venom, the property of dissolving is not restored to the latter. Pursuing his researches upon the bacteriolytic actions, Noc has also shown that the fresh serums of the rabbit, horse, guinea- pig, rat, and man are capable of destroying them completely. We must conclude from this that venom has the property of fixing the alexin of these fresh serums, and in fact it is easy to show that this fixation takes place by experimenting with haemo- lytic alexin, which is much more easy to study ; it is sufficient to eliminate the intervention of the hsemolysin proper to Cobra- venom. \ With this object, Noc employed horse-corpuscles (which are readily dissolved by fresh rat-serum), and neutralised the haemo- lysin proper to the venom by antivenomous serum, which has no effect upon fresh horse-corpuscles and upon the alexin of rat-serum. For experimental purposes six tubes are prepared with contents as follows :— (1) 0*5 c.c. of fresh rat-serum. (2) 0"5 c.c. of fresh rat-sexum -|- 0'5 milligramme of Cobra- venom (0-5 c.c. of a solution of 1 in 1,000). (3) 0'6 c.c. of fresh rat-serum -|- 1 milligramme of venom (after fifteen minutes' contact of the venom with the alexin in tubes 2 and 3 the venom is neutralised by 1 c.c. of antivenomous serum in the case of tube 2, and by 2 c.c. in that of tube 3). (4) 1 milligramme of venom. (5) 1 c.c. of antivenomous serum. (6) 0*5 c.c. of fresh rat-serum + 1 c.c. of antivenomous serum. To each tube 2 drops of defibrinated horse-blood are added, and the tubes are placed in the stove at a temperature of 35° C. In tubes 1 and 6, which contain fresh rat-serum alone, and fresh serum -f antivenomous serum, haemolysis appears in a few minutes. 14 210 VENOMS In tube 4, which received venom alone, hyeiuolysis is also produced in one hour. It is not produced at all in tubes 2 and 3, which received the neutral mixture of fresh serum and venom, proving that the hsemolytic alexin has been fixed by the venom. ' The latter, therefore, here plays the part of a true fixator or amhuceptor. Venom behaves, in short, after the manner of extracts of organs. The fixation of hsemolytic alexin by extracts of organs, the tissues, and animal cells (liver, spleen, spermatozoids, &c., &c.), has already been demonstrated by V. Dungern, P. Miiller, Levaditi, and E. Hoke. The same fact is also observed with solutions of peptone. The fixation of alexin is therefore a general property of certain albuminoid molecules. It was interesting to endeavour to reproduce, with Co6m-venom, J. Bordet's experiments upon alexins and anti-alexins. It was to be hoped that we had in this substance an anti-alexio body capable of being preserved for an indefinite time and constant in its activity, which would enable us easily to measure the dose of alexin con- tained in a small quantity of a serum, or other Uquid of leucocytic origin. The experiment proved to Noc that, contrary to the ideas of Ehrlich and his pupils, and conformably to the results obtained by Bordet with serums and toxins, the neutralisation of venom takes place in a variable ratio. If a dose A of fresh serum is capable of neutrahsing exactly 5 milligrammes of Co6ra-venom with regard to a sensitive microbe, on employing a dose of the strength of 2 A we ought to find a bactericidal dose, 1 A, in the excess of serum, according to the theory of definite proportions. No such bactericidal action is seen, however ; the serum, on the other hand, acts in the contrary direc- tion by means of its nutritive substances, and in the mixture 2 A -H venom we obtain a larger number of colonies of micro-organisms than in the mixture A -|- venom. We see, then, that the property of cells of fixing in excess the active substance in serums, discovered by Bordet for the hj«moly- THE PHYSIOLOGY OF POISONING 211 sins (staining phenomena), is met with again in the case of extracts of organs, at least with regard to the bacteriolytic substance of Co&m-venom. It results, then, from the foregoing facts that Cobra-venom con- tains a cytolysin, which acts upon micro-organisms and is capable of fixing the alexin of normal serums. The application of these data to the living animal is evidently full of difdculties, by reason of the complexity of the substances that come into play. Let us see, however, to what extent they are capable of serving to explain the phenomena that are produced as the result of poisoning. ' It was observed by Kaufmann that the cadavers of animals which have died from snake-bite are very rapidly invaded by the bacteria of putrefaction. Welch and Bwing, referring to these phenomena of rapid putrefaction in cases of death from venom, explained them as being due to the loss of the bactericidal power of the serum. In hot countries, even when snake-bites are not fatal, they are frequently complicated by local suppuration or gangrene, occasioned by micro-organisms introduced at the time of the bite. The minute analysis of the phenomena of poisoning shows, in reality, that the organism undergoes different modifications accord- ing to the quantity of venom injected and its channel of penetration. When the dose of venom is rapidly lethal, whether because it penetrates into the veins or because a larger amount of it is diffused beneath the skin, it occasions a transient hypoleucocytosis, which is, moreover, a reaction common to injections of venom, pro-peptone, extracts of organs, and microbic toxins (Delezenne, Nolf). It follows that blood collected a short time after the injection may be totally bereft of its bactericidal power, in consequence of the dis- appearance of the leucocytes, which have migrated into the organs. Thus it was observed by S. Flexner and H. Noguchi that the serum of a rabbit, treated with 10 milligrammes of Gobra- venom, showed, fifty-seven minutes after the injection, a great loss of bactericidal properties. But it is impossible to conclude, from 212 VENOMS the diminution of bactericidal power in this experiment, that the alexin becomes fixed by the venom. Since the secretion of alexin is connected with the presence of leucocytes, the hypoleucocytosis due to the venom is sufficient to explain the loss of bactericidal power. Nevertheless, the action of venom is not confined to these physiological phenomena ; in diffusing itself through the organism it stays more especially in parts where the circulation has become slower, in the capillaries of the organs where the leucocytes that have disappeared from the general circulation are already to be found agglomerated and altered. Here the cytolysins of the venom, continuing their effects, are capable of neutralising the alexins set at liberty by the destruction of the leucocytes, and thus the rapid multipHcation of the bacteria of putrefaction, which have come from the intestine or were carried in with the bite, is easily explained. In the same way, we can account for the suppuration that is met with as a compHcation of non-lethal bites, in spite of the hyperleucocytosis consequent upon the penetration of a weak dose of venom ; immediate neutrahsation of the alexin set at liberty at the level of the wound has sufficed to enable micro-organisms to multiply. D —Various Diastasic Actions of Venoms. So long ago as 1884, de Lacerda, in his " Lecons sur le venin des serpents du Bresil," described the results of his researches upon the diastasic actions of venom. He proved that venom emulsifies fats, causes milk to curdle, and does not saccharise starch. But the 'solutions of venom employed by this author were not sterile, so that putrefactive phenomena may be believed to have occurred in the course of his experiments. The subject has been studied afresh by Wehrmann ' in my laboratory, and afterwards by Lannoy.^ These two investigators ' Annates de VInstitut Pasteur, 1898. These Paris, No. 1138, 1903. THE PHYSIOLOGY OF POISONING 213 have shown that venoms do not hydrolyse either starch or inuhn. Co6?*a-venom and that of Vipera change saccharose very sHghtly. Tbey do not modify the glucosides (amygdahn, coniferin, sahcin, avbutin, and digitahn) ; they therefore do not contain emulsin. On the other hand, these venoms possess, as I have already stated, very interesting kinasic properties, which have been pointed out by Delezenne.^ They consist in the fact that while venom alone is incapable of digesting cooked albumin, we have only to add to a pancreatic juice, in itself devoid of effect upon albumin, a trace of venom, to see this albumin immediately become digested. Z/ac/iesis-venom is especially active in this respect. In Dele- zenne's experiments it was generally sufficient to add to 1 c.c. of inactive pancreatic juice, 0'5 to 1 c.c. of a 1 in 1,000 solution, that is 0"5 to 1 milligramme of venom, to obtain the digestion of a cube of albumin weighing 0"5 gramme in the space of from ten to twelve hours. Much weaker doses, \, sometimes even -^--q of a milli- gramme still gave the same result, with this sole difference that digestion took twenty-four, forty-eight, and even seventy-two hours to become complete. Co&?-a-venom was found to be a httle less active than the fore- going, but still its action was usually evident enough when it was employed in a dose of 0"5 milligramme or even O'l milligramme. As for the venom of Vipera herus, it was often necessary to employ it in doses from five to ten times stronger in order to obtain the same result. Delezenne has ascertained, on the other hand, that these venoms entirely lose their kinasic power when they are subjected to ebulli- tion for fifteen minutes. This kinase or diastase, capable of quickening the inert pan- creatic juice, mui5t evidently be of very great utility to the reptile in enabling it to digest its prey. Venom, therefore, is not, as has long been believed, a purely defensive secretion ; it corre- sponds to a physiological necessity, like that of the intestinal or ' Comptes rendus de VAcademie des Sciences, August 11, 1902. 214 VENOMS pancreatic juice. Herein is to be found tlic explanation of the fact that the non-poisonous snakes, although destitute of organs of inoculation, possess supralabial or parotid glands which produce venomous saHva. Experiments have been made by Ch. Fere' to determine the effect upon the development of the embryo of the introduction of venom into the albumen of the egg of the fowl. He found that 83 per cent, of the embryos, developed in eggs intoxicated with 0-05 milhgramme of viper-venom and opened after being incubated for seventy-two hours, exhibited various anomalies in development. E. — Action of Vaeious Diastases upon Venoms. Venoms are modified or destroyed by certain normal diastases of the organism. It was shown long ago by Lacerda, Weir Mitchell, Sir Joseph Fayrer, and Lauder Brunton, that it is possible to introduce without danger into the stomachs of adult animals amounts of venom many times greater than the lethal dose. I have repeatedly verified this, but have nevertheless observed that young mammals, while being suckled, readily absorb venom by their alimentary canal, and succumb to the ingestion of doses scarcely larger than those which kill when subcutaneously injected. Here we have a very important fact, which once more proves how easily the intestinal mucous membrane of young animals is permeated by toxins. By my instructions Wehrmann^ and Carriere,' in my laboratory, have studied the modifications undergone by venoms in the alimentary canal of rabbits. We have seen that these animals can ingest without inconvenience doses of venom 600 times greater than the lethal dose, and that, if we cause these ingestions to be' repeated several times, contrary to the assertion of Fraser'' (of ' Comptes rendus de la 8oci6t6 de Biologie, January 11, 1896. ' Wehrmann, Annales de VInstitut Pasteur, 1897 and 1898. Carriere, " Sur le sort des toxines efc des antitoxines dans le tube digestif," ihid., 1898, p. 435. * British Medical Journal, 1895 and 1897. THE PHYSIOLOGY OF POISONING 215 Edinburgh), we never succeed in obtaining immunity to the sub- cutaneous injection of a simple lethal dose, and no antitoxin is formed in the blood. The ptyalin of the saliva, pancreatic juice, and hile destroy Gohra-N&OLom in vitro. We must, therefore, assume that these diastases are veritable agents of destruction for ingested venom. The intestinal microbes play no part, any more than the intestinal juice by itself. The gastric juice has very little effect. Papain is almost as active as the pancreatic juice. It had already been proved by Fraser, so long ago as 1895, that bile, after prolonged contact and in a sufficient dose, has a strongly destructive effect upon Cobra-venom ; but, contrary to the opinion of this investigator, it is not antitoxic, for it possesses no preventive or curative property, and its effects are produced only in vitro. We see from what has been stated above, that venoms intro. duced into a sensitive organism are capable of producing extremely complex effects upon the various tissues or humours. They act on the nerve-cells by their netirotoxin, on the endothelium of the blood-vessels by their liaviorrhagin (Flexner and Noguchi), on the red corpuscles by their Imviolysin, on the fibrin of the blood and muscles by their proteolytic diastase, and on the fibrin-ferment itself by their thrombase. They also act on the leucocytes, according to the experiments of Chatenay,^ performed under the direction of Metschnikoff, and according to those of Flexner and Noguchi,^ already cited. Thus we understand how complex must likewise be the means of defence that have to be employed in order to afford an effective protection against such poisons. The slightly intoxicated organism at first reacts by the inter- vention of the leucocytes ; a hyperleucocytosis is produced, accom- ' Chatenay, "Les reactions leucocytaires vis-^-vis de certaines toxines," TJiese Paris, 1894. * Flexner and Noguchi, " Snake-venom in Relation to Hsemolysis, Bacterio- lysis, and Toxicity," Journal of Experimental Medicine, vol. vi., March 17, 1902. 216 VENOMS panied by a more or less considerable rise of temperature. After a few hours everything returns to its normal condition, and if the injection of a lethal dose of venom is repeated several times, at intervals of a few days, it is not long before antitoxic substances are found to appear in the serum. When the dose of venom injected is sufficient to cause death, we observe, a very few moments after the injection, a lowering of temperature and a hyjjoleucocijtosis, which is the more pronounced in proportion to the nearness of the dose of venom to the minimal lethal dose. With very strong doses the hypoleucocytosis has not time to manifest itself. It is therefore probable that, in intoxication by venoms as in that by the toxins of micro-organisms, the protective role of the leucocytes is all-important, not only because these cells are capable of digesting venoms owing to their protoplasmic digestive juices, but also because they constitute if not the only, at an)' rate the principal source of the antitoxic substances or amboceptors. 217 CHAPTER X. TOXICITY OF THE BLOOD OF VENOMOUS SNAKES. Seveeal physiologists, among whom it is right to mention Fontana/ Leydig/ Eeichel,' Eaphael Blanchard,'' PhisaHx and Bertrand,^ and S. Jourdain,'' have pointed out the presence of poison-glands in Tropidonotus natrix or other non-venomous snakes, and have explained the immunity enjoyed by these animals with regard to venom as being due td the existence of an internal secretion of this poison. We also know, from the writings of Phisalix and Bertrand, that the blood of the viper, and that of the salamander and toad are toxic. For my part I have found' that the blood of Naja, Bitngarus, Lachesis, and Cerastes possesses the same properties, and a comparative study has been made by Wehrmann,^ in my laboratory, of the toxicity of the blood of the viper and of that of the blood of the eel, already established by Mosso (of Turin).^ It is remarkable to find that the blood of the various venomous or non-venomous snakes, like that of certain fishes, such as eels, produces, when injected beneath the skin or into the peritoneum, local a,nd general effects very similar to those of venoms. Injec- tions of 0-5 c.c. to 1 c.c. of the blood of the viper or of the common ' " Trattado del veneno della vipera," 1787. - Archiv fii/r milcrosTcoinsclie Anatomie, Bd. ix., 1873. ^ Morpliologisches Jalirbuch, Bd. viii., 1883. * Comptes renclus cle la Societe de Biologic, January 20, 1894. " Arclvives de Phyaiologie, 1894. Comptes rendus de I' Academic des Sciences, Paris, January 22, 1894. ' Comptes rendus de la Societe de Biologic, January 13, 1894. ■* Annales de I'Institut Pasteur, 1897. " ArcJiives italiennes de Biologic, 1888 and 1889. 218 VENOMS snake, beneath the skin of the guinea-pig, provoke an intense local reaction, which always results in the formation of an eschar. The injection of slightly stronger doses, 1 c.c. to 2 c.c, into the peri- toneum, ahnost always kills these animals, like venom, with symp- toms of respiratory asphyxia. The blood of Naja tripudians, injected subcutaneously, is lethal to the mouse in a dose of 0"25 c.c. When this blood is heated, after having been suitably diluted with threfe or four parts of distilled water, in order to prevent it from coagulating, it is found that a temperature of 70" C. maintained for fifteen minutes is sufficient to cause it to lose all toxic efifect. The same applies to the blood of the other poisonous or non- poisonous snakes, and to that of the MurcenidcB. Now, since the majority of venoms resist even prolonged heating at this temperature, it cannot be supposed that the toxicity of the blood is due to its containing venom derived from the internal secretion of the poison-glands, as was thought by Phisaiix and Bertrand. On the contrary, it is probable that the toxicity results from the fact that the blood contains diastasic substances of cellu- lar origin, which themselves represent certain of the constituent elements of venoms. These substances, moreover, possess some of the properties of venoms, as, for instance, the faculty of producing haemorrhages and of being influenced by antivenomous serum, which causes ' them to lose a large portion of their toxic qualities. I have found that they can even be utilised to vaccinate animals • against venom; by injecting weak, non-lethal, and repeated doses of dilute Co&ra-blood into guinea-pigs and rabbits, I have succeeded in rendering them immune to doses of Co&ra- venom several times greater than the lethal dose. There is no doubt that it is to these substances that the poisonous and non-poisonous snakes owe the partial immunity that they themselves enjoy with respect to venoms. We know, in fact, that common snakes suffer without danger many bites from TOXICITY OF THE BLOOD OF VENOMOUS SNAKES 219 vipers (Phiscalix and Bertrand'), and that the Cobra is relatively httle affected by inoculation with its own venom or with that of other Colubrid^, such as Bungarus, or even of ViPRRiDiE, such as Vipera russellii. This immunity, hov^ever, is far from being absolute ; I have killed common snakes {Tropidonotus natrix) with doses of viper- venom ten times greater than the lethal one for the rabbit, and Lachesis lanceolatus (from Martinique) with 0'02 gramme of the venom of Naja tripudians. Phisalix,^ on his part, has shown that, while it was necessary to inject from 100 to 200 milligrammes of viper-yenom. into other vipers or common snakes, beneath the skin or into the peritoneum, in order to cause death, the introduction of only 2 to 4 milligrammes of this venom into the brains of these reptiles was sufficient to kill them with the same symptoms of intoxication. This dose, how^- ever, is only twenty-five to thirty times greater than the lethal one for the guinea-pig. The practical lesson to be learnt from the establishment of the foregoing facts is that poisonous snakes of different species must never be placed in the same cage, for these animals sometimes bite each other, and may thus kill one another. Simon Flexner and Noguchi ^ have studied the action of the serums of Grotalus, Ancistrodon, and a non-poisonous species, the pine snake {Pituophis catenifer), on the venoms of Naja, Ancis- trodon, and Grotalus. They found that the serum of Grotalus rapidly dissolves the red corpuscles of man, the dog, rabbit, guinea- pig, sheep, rat, pigeon, and horse. The serum of the pine snake affects the same red corpuscles, but in a lesser degree. Heating to 58° C. suppresses the haemolytic power of these serums, but they can be restored to activity by the addition of a very small quantity of the same serum in a fresh ' Archives de Physiologic, 1894. ^ Gomptes rcndus de la Societe de Biologie, July 25, 1903. Journal of Pathology and Bacteriology, May, 1903. 220 VENOMS condition, of fresh serum derived from other snakes, or of fresh serum from the guinea-pig. Antivenomous serum also, when added in a suitable dose, entirely suppresses the ha3molytic action of snake-serums ; it has, however, greater effect upon the hsemolysin of Cobra-hlood than upon that of the blood of other snakes. This observation had previously been made by W. Stephens,^ and it has been verified by Noc in my laboratory. Crotalus-serxim dissolves the red corpuscles of the mongoose {Herpestes ichneumon) of Jamaica, whose extraordinary resistance to venom is well known. But if variable doses of Ancistrodon- venom and Grotalus-sexxxm be made to act simultaneously upon these corpuscles, the latter are no longer dissolved. Again, if, instead of red corpuscles which are but little sensitive, like those of the mongoose, we employ the highly sensitive corpuscles of the guinea-pig, the result is the same. These experiments are regarded by Plexner and NogQchi as proving that the amboceptors of the toxic serum become fixed, in conformity with Ehrlich's theory of the lateral chains, upon the receptors of the sensitive erythrocytes, and leave no more receptors free for the fixation of the venom. The same investigators have endeavoured to determine the respective toxicity of the tissues of the different organs of Grotalus. They found that the most toxic organs are the spleen and the liver ; the toxicity of the spinal cord, kidney and muscles is much less. It appears that this toxicity is intimately connected with the quantity of blood that the tissues retain, for the physiological effects observed are identical with those that follow the injection of blood or serum alone. They also ascertained that the contents of the eggs of Grotalus are especially rich in poison, and this poison appears to consist for the most x^art of neurotoxin, since it does not cause haemorrhages. Phisalix has observed that the ovules of the viper exhibit analogous toxicity.^ ' Journal of Pathology and Bacteriology, 1900, p. 273. * Comptes rendus de la Sociite de Biologie, July 1, 1905. TOXICITY OF THE BLOOD OF VENOMOUS SNAKES 221 Summing up what has been stated above, we find that the blood of both poisonous and non-poisonous snakes contains toxic substances, destructible by heating to 68° C, and physiologically distinct from venoms,' but like the latter possessing the property of dissolving the red corpuscles of the majority of vertebrates and of producing haemorrhages. ■ 222 CHAPTER XI. NATURAL IMMUNITY OF CERTAIN ANIMALS WITH RESPECT TO SNAKE-VENOMS. It was long ago pointed out that certain warm-blooded animals, including the mongoose [Herpesfes ichneumon, Family Viverrida), hedgehog (Erinaceus europaus, Family Erinaceiclce) , pig {Sus scrofa, Family Suidce), and some herons {Ajaja, Subfamily Plata- leincB ; Cancro^na, Subfamily CancromincB : Botaurus, Subfamily ArdeincB : Mijcteria, Subfamily CiconiincB), known in Colombia under the names Culehrero and Guacabo, exhibit a natural immunity with respect to snake-bites. Pigs devour vipers with great readiness, and in the region of North America which adjoins the Mississippi and its tributaries they are even trained to destroy the young rattle-snakes and other poisonous serpents with which the valleys of these watercourses are infested. During my stay in Indo-China I inoculated a young pig, beneath the skin of the back, with a dose of Cobra-venom (10 milligrammes) capable of killing a large-sized dog. The animal withstood the injection, but I am inclined to think that this is not a case of true immunity ; it is probable that the pig owes its resistance to venom to the fact that its skin is lined with an enormous layer of adipose tissue, which is but very slightly vascular, and in which absorption takes place very slowly. This opinion is corroborated by my dis- covery that the serum of this animal is entirely destitute of any antitoxic substance. I mixed a dose of Co&m- venom, lethal for the rabbit, with 3'5 and 8 c.c. of pig-serum. These mixtures killed rabbits in the same time as the controls that received the venom NATUBAL IMMUNITY OF CERTAIN ANIMALS 223 diluted with equal quantities of rabbit-serum or physiological saline solution. The natural imuaunity of the mongoose and the hedgehog rests upon mofe scientifically established facts. My own experiments upon the immunity of the mongoose were made with six specimens of these little carnivores captured in Guadeloupe (ifrench West Indies), an island in which no poisonous snakes exist ; consequently their immunity could not have arisen from their having become accustomed to the bites of venomous reptiles. I first introduced a mongoose into a cage containing a Naja biingarus {Ophiophagus) of large size. The snake rose up imme- diately, dilated its hood, and struck savagely at the little animal, which, darting nimbly out of the way, escaped being seized and, frightened for a moment, took refuge in a corner of the cage. Its stupor, however, was but of brief duration, for at the very moment when the hamadryad was preparing to strike at it again, the mongoose, with open mouth and snarling, sprang upon the reptile's head, bit it hard in the upper jaw and crushed its skull in a few seconds. This scene is in every respect reminiscent of the admirable description given by Rudyard Kipling, in his celebrated "Jungle Book," of the great war that Bikki-tikki (the Mongoose) fought with Nag (the Cobra) " through the bathrooms of the big bungalow in Segowlee cantonment " : — "Nag was asleep, and Rikki-tikki looked at his big back, wondering which would be the best place for a good hold. 'If I don't break his back at the first jump,' said Eikki, ' he can still fight ; and if he fights — 0 Eikki ! ' He looked at the thickness of the neck below the hood, but that was too much for him ; and a bite near the tail would only make Nag savage. "'It must be the head,' he said at last; 'the head above the hood ; and when I am once there, I must not let go.' " Then he jumped. The head was lying a little clear of the water-jar, under the curve of it ; and, as his teeth met, Eikki braced 224 VENOMS his back against the bulge of the red earthenware to hold down the head. This gave him just one second's purchase, and he made the most of it. Then he was battered to and fro as a rat is shaken by a dog— to and fro on the floor, up and down, and round in great circles ; but his eyes were red, and he held on as the body cart- whipped over the floor, upsetting the tin dipper and the soap-dish and the flesh-brush, and banged against the tin side of the bath. As he held he closed his jaws tighter and tighter, for he made sure he would be banged to death, and, for the honour of his family, he preferred to be found with his teeth locked. He was dizzy, aching, and felt shaken to pieces, when something went off like a thunder- clap just behind him ; a hot wind knocked him senseless, and red fire singed his fur. The big man had been wakened by the noise, and had fired both barrels of a shot-gun into Nag just behind the hood."i From the experimental point of view, these stirring battles between mongooses and cobras only show that a mongoose of the size of a large squirrel makes a plucky and victorious attack upon a venomous reptile of the most dangerous species and of very large dimensions ; but it is impossible to tell with certainty whether the mongoose has been bitten. I therefore inoculated a second mongoose with 2 milHgrammes of venom, a lethal dose for 4 kilogrammes of rabbit. The animal did not experience the slightest malaise. I then took blood from three other mongooses, by tying a carotid without kilhng the animals. This blood, mixed with venom or injected as a prophylactic into rabbits, exhibited an antitoxic power, which, though evident, was of httle intensity, and insufficient in all cases as a certain preventative of death. All the rabbits that received a preventive dose varying from 2 to 7 c.c. of mongoose-serum succumbed to inoculation with venom, but with a considerable retardation (from two to five hours) as compared with the controls. ' "The Jungle Book," by Eudyard Kipling. London: Macuiillan and Co., Ltd. Reprint of 1905, pp. 183, 184. NATURAL IMMUNITY OF CEBTAIN ANIMALS 225 I endeavoured to determine the limit of tolerance of the mon- goose with respect to venom. Two of these animals, which had never been inoculated, received doses of venom respectively four times and six times lethal for the rabbit. The first mongoose remained perfectly well ; the second was ill for two days, and then recovered. A third mongoose, into which I injected a dose eight times lethal for the rabbit, succumbed in twelve hours. Fig. 89. — Mongoose seized by a Cobea. (For this illustration I am indebted to the kindness of M. Claine, late French Consul at Rangoon.) It must be concluded from these facts that the West Indian mongoose is but little sensitive to venom; that it is capable of withstanding, without malaise, doses which are considerable in pro- portion to its size, but that its immunity is far from being absolute. If it is generally the victor in its combats with poisonous snakes, the result is mainly due to the extreme agility with which it is endowed. 15 226 VENOMS A number of experiments have been made by Lewin/ and by Pbisalix and Bertrand/ upon the immunity of the hedgehog to the venom of Vipera berus. It had long been known that hedgehogs are inveterate hunters of vipers, which they devour with avidity. Thanks to the long and sharp spines by which their bodies are protected, they avoid being bitten and contrive to catch the reptiles very cleverly, but it occasionally happens that they do not escape being struck. How- ever, even in these cases they rarely succumb. Inoculation with fairly large quantities of venom does not make them ill : the dose of uiper-wenom lethal for these small animals is about forty times greater than that which kills the guinea-pig. Their power of resistance is therefore beyond doubt. It may be asked whether this is due to their blood normally containing antitoxic substances. In order to elucidate this question, Phisalix and Bertrand first proved that the blood of normal hedgehogs is toxic to laboratory animals, especially to the guinea- pig. A mixture of this blood with viper-venom cannot therefore be harmless. But it sufficed to heat hedgehog blood to 58° C. to cause it to lose its toxicity, and it was found that it then became antitoxic. Gruinea-pigs inoculated in the peritoneum with 8 c.c. of heated hedgehog-serum were able to withstand, immediately afterwards, twice the lethal dose of viper-venom. It really seems, therefore, that the resistance of the hedgehog to venom is due to the presence of antitoxic substances in its blood. But, as in the case of the mongoose, there is no question here of genuine immunity. The same is probably true with respect to the herons of Colombia, the Gulebrero and Guacaho, which eagerly search after • Deutsche medicinisclie WochejiscJu'ift, 1898. ^ Gomptes rendus de la Societe de Biologic, 1895, p. 639, and 1899, p. 77 ; Bulletin du Museum d'Histoire naturelle, 1895, t. i., p. 294, t. ii., p. 100. NATURAL IMMUNITY OF CERTAIN ANIMALS 227 young snakes for food. No investigations, however, have yet been made upon this subject. These birds, moreover, are few in number ; hunters pursue them for the sake of their brilhantly coloured plumage, and it is to be regretted that no attempt is made to prevent their destruction, or to acclimatise them in countries in which poisonous snakes constitute a veritable calamity, such as Martinique, St. Lucia, or India. 228 CHAPTER XII. SNAKE-CHABMEBS. In all the countries of the globe where poisonous snakes are formidable to man, there are certain individuals who profess to be secure from all ill-effects from the bites of these reptiles, whether because they are immune to venom, or because they possess secrets which enable them to cure themselves when they happen to have been bitten. Not unnaturally these secrets are sometimes turned to profitable account, and the possessors of them generally enjoy considerable popular influence, and are very highly venerated. Intimate relations with the divinities are freely attributed to them. Among the Eomans the jugglers who carried on the profession of snake-charmers and healers of snake-bites were known as Psylli. Plutarch tells us that Cato, who loved not doctors because they were Greeks, attached a certain number of them to the army of Libya. They were accustomed to expose their children to serpents as soon as they were born, and the mothers, if they had failed in conjugal fidelity, were infallibly punished by the death of their offspring. If, on the contrary, the children were lawful, they had nothing to fear from the bites of the reptiles. "Bece^is etiam editos serpentibus offer ehant ; si essent partus aduUeri, matrum crimina plectabanhir interitu parviilorum ; si pudici, probos ortus a morte paterni privilegium tuebatur" (Solinus). The Libyian Psylli of antiquity still have their representatives in Tunis and in Egypt. Clot Bey writes as follows with reference to the Egyptian Psylli : — " The Ophiogeni, or Snake-charmers, have been renowned from SNAKE- CHABMEBS 229 all time. Strabo speaks of them, and Prosper Alpinus was a witness of the singular effects of their art. The majority of modern travellers who have visited Egypt have been equally struck with the freedom with which they handle poisonous reptiles and animals. " The Psylli go from house to house, caUing forth and charming the snakes that they may happen to contain. They claim to attract them by means of a particular power. Armed with a short wand, they enter the chamber to be purged from these venomous guests, make a smacking noise with their tongue, spit upon the ground, and pronounce the following incantation : ' I adjure you, by God, if you are loithout or ivithin, to appear ; I adjure you, by the greatest of names ; if you are obedient, appear ! If you disobey, die ! die ! ' The snake, submissive to this command, departs forthwith, issuing from a crack in the wall or floor. India is pre-eminently the country of snake-charmers. There exists an entire caste of Hindus, called Mai, who are professional catchers and vendors of snakes, but do not perform tricks with them. The snake-charmers are recruited from among another caste, that of the Sangis or Tubriivallahs of Bengal. These men, who are usually clothed in yellow robes and wear large turbans, manage the Cobra with really marvellous skill. All travellers who have had the opportunity of crossing India or of touching at a port on the coast or on that of Ceylon have witnessed scenes similar to that described by Natalis Eondot (figs. 90 and 91) :— " Towards six o'clock in the evening a Hindu juggler comes on board. He is poorly clad, and wears a turban decorated with three feathers, and several necklaces of those amulet-sachets called gris-gris in Senegal. In a flat basket he carries a spectacled Cobra- di-Capello. ' " Aper9u general sur I'Egypte." Paris, 1840. Fig. 90. — Indian Snake-chahmee at Colombo (Ceylon). Fig. 91.— Indian Snake-chabmek at Colombo (Ceylon). 232 VENOMS " This man instals himself on deck ; we sit down on the seat provided for the officer of the watch, and the sailors form a circle. The basket is placed on the deck and uncovered the Cobra is coiled up at the bottom of it. The juggler squats a few paces off and commences to play a slow, plaintive, and monotonous air, with a kind of small clarinet (fig. 92), the sounds of which recall those of the Breton hiniou. Fig. 92.— Musical Insteument used by Indian Snake-chahmers to Charm Cobras. (For this figure I am indebted to the kindness of Dr. Pineau.) " By degrees the snake moves, extends itself, and then assumes an erect posture, but without quitting the basket. It begins to appear uneasy and endeavours to recognise its surroundings ; it becomes agitated and irritated, expands and spreads out its hood, breathes hard rather than hisses, and frequently and quickly shoots out its slender forked tongue ; several times it makes a violent dart as though to attack the juggler ; it frequently trembles, or rather gives sudden starts. The juggler keeps his eyes always fastened upon the snake, and gazes at it with a singular fixed stare. After some time, about ten or twelve minutes, the Cobra becomes less animated, grows quiet, and then sways as though influenced by the slow and monotonous rhythm of the musician ; it keeps inces- santly darting out its tongue. Little by little it is brought to SNAKE-CHABMEIiS 233 a sort of somnolent condition. Its eyes, which at first watched the juggler as though in order to take him by surprise, are, to a certain extent, fixed and fascinated by the latter's gaze. The Hindu' takes advantage of this moment of stupefaction on the part of the snake by approaching it slowly without ceasing to play, and touches the head of the Cobra, .first with his nose and then with his tongue. Although this takes but an instant the reptile starts out of its sleep, and the juggler has barely time to throw himself backwards so as not to be struck by the snake, which makes a furious dart at him. " We doubt whether the Cobra still has it fangs, and whether the Hindu incurs any real danger in approaching it. Accordingly we promise our man a Spanish piastre if he will make the snake bite a couple of fowls. A black hen, which struggles violently, is taken and offered to the Cobra, which half rises, looks at the bird, bites it, and lets it go. The fowl is released and runs off terrified. Six minutes later, by the watch, it vomits, stretches out its legs, and dies. A second fowl is placed in front of the snake, which bites it twice, and the bird dies in eight minutes." ^ Certain jugglers exhibit snakes from which they have taken care to extract the fangs ; they offer the animal a piece of cloth or soft stuff into which it drives its poison-teeth, and the fabric is then quickly snatched away in order by this means to break off the poison-fangs that have penetrated it. This operation is repeated at certain intervals with a view to preventing the reserve fangs from coming into use, and the reptiles can then be handled without any danger. It is unquestionable, however, and I have personally satisfied myself of the fact, that many genuine snake-charmers go through their performances with Cobras whose poison-apparatus is absolutely intact. That they almost always avoid being bitten is due to a perfect knowledge of the habits and movements of these reptiles. ' Brehm's " Thierleben" ; French edition, " Les Reptiles," p. 430. 284 VENOMS Nevertheless, a^ccidents sometimes happen to them, and every year a few of them succumb in pursuit of their caUing (see p. 370). Still, it may be asserted that some of them really know how to vaccinate themselves against venom, by making young Cobras bite them from time to time. It is stated by E. C. Cotes, ^ formerly of the Calcutta Museum, that the Indian snake-charmers do not extract the poison-fangs from their snakes. Even though deprived of its fangs, the snake would still be dangerous on account of its other teeth, the punc- tures of which would provide another channel for the penetration of the venom. Snake-charmers pretend that they owe their immunity to graduated inoculations. This is not yet conclusively proved ; what is better established is that they take the greatest care to avoid being bitten, and that in so doing they display the most remarkable skill. Even in France we are acquainted with professional viper- catchers, who employ the method of graduated inoculations in order to render themselves immune to the bites of indigenous reptiles. One of these men, who lives near Arbois (Jura), takes good care to get himself bitten, at least once a year, by a young viper; when he forgets this precaution and happens to be bitten, he always feels the effects much more severely. Eraser^ (of Edinburgh) thinks that the repeated ingestion of small quantities of venom may suffice to confer immunity, and he mentions a certain number of experiments performed by him upon white rats and kittens, from which it would appear that the in- gestion of venom, continued for a long time, finally renders these animals absolutely refractory to subcutaneous inoculation with doses of the same venom several times greater than the lethal one; He therefore concludes that this process of vaccination may prob- ably be in use among snake-charmers. ' Maclure's Magazine, Apiil, 1894. 2 British Medical Journal, August 17, 1895. SNAKE- CHABMEBS 235 I have subnaitted this hypothesis to the test of experiment. I succeeded in making adult rabbits, guinea-pigs, and pigeons absorb enormous doses of Cohra-Yenom. by way of the alimentary canal. In this manner I have administered doses as much as a thousand times greater than the lethal one, yet I have never been able to prove that the serum of these animals became antitoxic. On the other hand, I have succeeded in vaccinating very young guinea-pigs and young rabbits which were still being suckled, by making them absorb, every second day, minimal and certainly in- nocuous doses of very dilute venom. In the case of young animals, venom is not modified by the digestive juices, and a portion of it is absorbed by the mucous membrane of the intestine. When the dose ingested is suitably reduced they withstand it, and when these ingestions are repeated every second or third day during the first weeks of life, the animals become perfectly vaccinated against doses certainly lethal for controls of the same age and weight. But it is always difficult to push the vaccination far enough for the serum to acquire antitoxic properties, and I have never been able to prove the appearance of the latter. I think, however, that it ought to be possible to arrive at this result by experimenting upon animals such as lambs, kids, calves, or foals, the intestine of which remains permeable to toxins for a sufficiently long period. It may be that certain snake-charmers, who claim to possess family secrets which they transmit from father to son, employ an analogous method in order, in their infancy, to confer immunity to venoms upon those of their male children who are to inherit their strange and lucrative profession. In Mexico, certain Indians called Curados de Culebras know how to acquire the privilege of being able to be bitten by poisonous snakes without the least danger to life, by inoculating themselves several times with the teeth of rattle-snakes. Dr. Jacolot,^ a naval surgeon, while staying at Tuxpan, made Archives cle medecine navale, 1867, p. 390. ^<>^ VENOMS enquiries as to these Curados de Culehras, and was able to satisfy himself that their immunity is an actual fact. The process of vaccination employed by the natives of Tuxpan is as follows : — A preparatory treatment is necessary. On the very day on which a man is to inoculate himself or get himself inocu- lated, he takes from 5 to 15 tubers of a plant known by the name of Mano de Sapo {i.e., Toad's hand, Dorstenia contrayerva, Family XJrticacecB) . These tubers must — and this is absolutely necessary — be administered on a Friday, and always in an odd number, 5, 7, 9, &c., up to 15, according to the tolerance of the subject. If the plant be gathered on the first Friday in March it possesses its marvellous properties in the highest degree ; in this case, even if it be dry, it is still excellent for the preparatory stage of the inoculation. The physiological effects of mano de sapo are not very marked : the circulation is slightly diminished and a sensation of cold is experienced, but there are no nervous troubles. The subject frequently has attacks of vomiting or nausea. The inclination to vomit must be fought against, for if the plant should happen to be rejected is would be dangerous to submit to the inoculation. The root of the mano de sapo is usually taken fresh. There is another indispensable precaution : while undergoing this treat- ment it is necessary to abstain from all sexual intercourse for three days after the first inoculation, for two days after the second, and for one day after the third. For the inoculation a large snake's tooth, that is to say, one of the fangs, is employed, and the fangs of the most poisonous snakes, such as the rattle-snake {cuatro narices), are selected. The snake must be killed on a Friday, and the fangs extracted the same day. The same fang may serve for several ye&vs ! The inoculation is commenced on the dorsal surface of tbe left foot ; care must be taken to avoid coming into contact with a vein. The skin is torn with the point of the fang, so that it bleeds a little, and the incision is in the shape of a square. SNAKE-CHARMEBS 237 From the left foot the operator passes to the right wrist (anterior surface), then to the right foot (dorsal surface), and left wrist (anterior surface), always changing from one side of the body to the other. Operations are continued on the left thigh, then on the right arm, right thigh, and left arm ; in this way all the limbs are inocu- lated. On the body an inoculation is made in the centre of the sternum; another is made in the nape, and a final one in the centre of the forehead. The finishing touch is given with the semblance of a square incision in the tongue. At least seven series of similar inoculations are necessary to protect a man from the spells of the serpent, and at the same time to confer upon him the faculty of curing by suction the bites of the venomous snakes that are most dreaded. During the whole of the period in which the Indian thus sub- mits to successive inoculations, his health shows no noteworthy derangement. He feels a slight headache and a strange inclination towards alcoholic drinks. But when the moon is at the full, then indeed, an excitement which is dangerous in another way takes possession of him. His cerebral faculties become over-excited, and he feels that his senses are deserting him ; his eyes become blood- shot, and he is pursued and tormented by an irresistible impulse to bite. He has itching sensations in his gums, his mouth burns, and salivation is greatly increased. He feels that he is going to give way to the necessity to bite, and then he flees to the woods, where he bites the trees viciously, tears their bark and discharges his venom. His poisonous saliva mingles with the sap, and, sur- prising phenomenon, the tree withers and dies ! Woe to the man or animal who happens to be bitten by a Curado de Culehra in a fit of passion. The victim will die as quickly as if he had been bitten by a snake ! Almost all the semi-savage people of Guiana, and of the valleys of the Orinoco and the Amazons, as also the tribes of Central Africa and the races of India, possess witch-doctors, who pretend 238 VENOMS to be in possession of means to preserve themselves from snake- bites, which are just as ridiculous and infallible as the procedure described above. The archives of a criminal anthropology contain the story of a Lyonnese gold-seeker, who had himself immunised against venom by an aboriginal native of Guiana -J— " The Indian took, from a bottle which contained several of them, a tooth of the Grage (Lachesis atrox), an extremely poisonous snake, and with it made upon my instep three incisions about 3 centimetres in breadth. He allowed the wounds to bleed for a mmute. I then experienced a fainting sensation, and large drops of sweat rolled from my forehead. The wounds were next rubbed with a blackish powder. I have since learnt that this powder was composed of the liver and gall of the animal, dried in the sun and pounded up with the poison-glands. The blood immediately ceased to flow. The Indian chewed some leaves of a tree mixed with this powder, and, applying his lips to the sore, injected into it as much saliva as he could, making an effort as though to inflate a balloon. This completed the operation. " Since then I have been bitten seven times by different species of very dangerous snakes, such as the Grage, coral-snake, &c., and have never even had an attack of fever. The Galibi, Boni, and Emerillon Indians, the Bosse negroes, and all the aboriginal natives of Guiana employ the same method of procedure. They even pretend that this kind of vaccination is transmissible to their off- spring, and that the hereditary immunity is maintained through several generations." Some years ago Mons. d'Abbadie communicated to the Academic des Sciences ^ a note from Colonel Serpa Pinto relating to another method of vaccination employed by the natives of Mozambique, which the Colonel himself consented to undergo. ' Revue scientifique, 1892, p. 254. ^ Comptes rendus de V Academic des Sciences, February 24, 1896. SNAKE-GHABMERS 239 "I was vaccinated," writes Colonel Sei'P^- Pinto, "at Inham- bane (on the East Coast of Africa), among the Vatuas. These people extract the poison of a snake which is known in Portuguese as the Alcatifa {i.e., carpet), and is so called on account of the variegated colour of its skin, which resembles a carpet. I am not acquainted with the means employed in order to obtain the poison, which is mixed with vegetable substances, and forms with the latter a dark brown viscid paste. " Two parallel incisions, 5 miUimetres in length, are made in the skin, and into these is introduced the paste containing the poison. These incisions are made on the arms, near the junction of the radius and ulna with the carpal bones, on the back of the hand, on the back, on the shoulder-blades, and on the feet, near the great toes. After the operation the natives exact an oath that the vaccinated one will never kill a poisonous snake, because they say that henceforth the snake is his intimate friend, and they throw upon him an Alcatifa snake, which does not bite him. " After undergoing this operation my whole body was swollen up for a week, and I underwent every possible kind of suffering. "I have never been bitten by any snake, and cannot vouch for. the infallibility of this remedy. The Vatuas do so, however, and they never kill a snake. "A short time after having been vaccinated, I was stung, when in the Seychelle Islands, by a scorpion, which did me no harm. Ten years later, at the time of my journey across Africa, I was stung by another scorpion which hurt me dreadfully, and for a week I thought that I was going to die or lose my arm." Mystification and superstitious ideas plaj^, as we see, a very great part in this preventive treatment, which is undergone by the natives of certain countries and snake-catchers or charmers. But it is not very surprising that, thanks to successive and repeated inoculations, a man can succeed in acquiring sufficient immunity to preserve himself from snake-bites. In ancient times it was even pretended that it was possible for 240 VENOMS this immunity to be transmitted in certain cases by heredity, and thus we can understand how the profession of snake-charmer was hereditary in certain native families in India or Egypt. With reference to this subject, Professor Landouzy, in his fine work on serum therapeutics, quotes a passage from " The Pharsaha " of Lucan describing, in the year 60 A.D., the customs of the PsylH, a people encountered by the army of Cato during its sojourn in Africa. This passage is so interesting that I cannot refrain from reproducing it : — " Alone unharmed of all who till the earth By deadly serpents, dwells the Psyllian race. Potent as herbs then- song ; safe is their blood. Nor gives admission to the poison germ E'en when the chant has ceased. Their home itself Placed in such venomous tract and serpent-thronged Gained them this vantage, and a truce with death, Else could they not have lived. Such is their trust In purity of blood, that newly born Each babe they prove by test of deadly asp For foreign lineage. So the bird of Jove Turns his new fledglings to the rising sun. And such as gaze upon the beams of day With eyes unwavering, for the use of heaven He rears ; but such as blink at Phcebus' rays Casts from the nest. Thus of unmixed descent The babe who, dreading not the serpent touch. Plays in his cradle with the deadly snake.'" The only scientific conclusion to be drawn from the facts and statements that we have just set before the reader is that, under certain circumstances, man can unquestionably acquire the faculty of resisting intoxication by snake-venom, by conferring upon him- self a veritable active immunity by means of repeated inoculations of venom. We shall shortly see that the case is the same with regard to animals. ' " The Pharsalia of Lucan, translated into blank verse by Edward Eidlej', Q.C., sometime Fellow of All Souls' College, Oxford." (London : Longmans, Green and Co., 1896). Book ix., p. 296, lines 1,046 to 1,065. 241 PAUT III. ANTIVENOMOUS SEEUM THERAPEUTICS. CHAPTER XIII. VACCINATION AGAINST SNAKE-VENOM — PBEFABA- TION OF ANTIVENOMOUS SEBUM— ITS PBEVEN- TIVE FBOPEBTIES AS BEGABDS .INTOXICATION BY VENOM. So long ago as the year 1887 it was shown by Sewall, in an important paper on " Eattlesnake-Venom,"^ that it is possible to | render pigeons gradually more resistant to the action of this venom ' by injecting them with doses at first very small, and certainly incapable of producing serious effects, and then with stronger and stronger doses. In this way, although these httle animals are very sensitive, he succeeded in making them withstand doses ten times greater than the minimal lethal dose. A little later Kaufmann^ obtained the same result with the venom of Erench vipers. He did not, however, succeed in pro- ducing tolerance of doses more than two or three times greater than the lethal one. In 1892, at the time of toy first experiments with cobra- venom at Saigon,'^ I arrived at the conclusion that it was possible, by 16 ' Journal of Physiology, vol. viii., 1887, p. 203. ' " Les Viperes de France," p. 136 (1889). ^ Annales de VIvstitut Pasteur, 1892, p. 181. 242 VENOMS meaus of SLiccessive inoculations with heated venoms, to confer on animals a certain degree of resistance to doses invariably lethal to the controls. From 1894 onwards, the investigations pursued simultaneously at the Paris .Natural History Museum, by Phisalix and Bertrand, upon viper-venom, and at the Paris Pasteur Institute by myself, upon that of the cobra, and subsequently upon other venoms of various origins, led to much more definite results. These investi- gations show, on the one hand,, that by vaccinating guinea-pigs or rabbits, and taking certain precautions, it is possible to confer upon these small animals a really strong immunity to venom ; on the other hand, that animals vaccinated against cobra-venom are perfectly immune to doses of viper-venom or that of other snakes {Bungarus, Cerastes, Naja haje, Pseudechis) certainly lethal to the controls ; and lastly, that the serum of the vaccinated animals contains antitoxic substances capable of transmitting the immunity to other ani7nals} According to Phisalix and Bertrand, who, as w^e have stated, experimented only with viper-venom, the best method of vac- cinating the guinea-pig consists in inoculating a dose of 0'4 milli- gramme of this venom heated for five minutes at 75° C, and, forty-eight hours afterwards, the same dose of non-heated venom. The latter is always lethal to the control guinea-pigs in from six to eight hours. Vaccination against cobra-venom, which is much more toxic, is most surely effected by the method recommended by me, which consists in at first injecting small doses of this venom mixed with an equal quantity of a 1 per cent, solution of hypochlorite of lime. By degrees the quantity of venom is increased and that of the hypochlorite progressively diminished, and the injections are 1 Comptes rendus do VAcademie des Sciences, t. 118, February, 1894, p. 356> March, 1894, p. 720 ; Coviptes rendtis de la Socieie dc Biologic, February, 1894, pp. Ill, 120 ; Archives de Physiologic, JuJy, 1894; An7ialcs dc I'lvstifiit Fastcur, May, 1894, p. 275, April, 1895, p. 225. VACCINATION AGAINST SNAKE-VENOM 243 repeated every three or four days, while attentively following the variations in the weight of the animals. The inoculations are suspended as soon as emaciation supervenes, and resumed when the weight becomes normal again. After four injections of chloridated venom the chloride is omitted, and a direct inoculation made with one-half the minimal lethal dose of pure venom ; then, three or four days afterwards, the injection is increased to three-fourths of the minimal lethal dose ; and finally, after the lapse of another three or four days, a lethal dose is injected. If the animals prove resistant, the vaccination can thenceforth be pushed on rapidly, and the quantity of venom injected each time can be increased, testing the susceptibihty of the organism by the variations in weight. As a rule, three months are necessary for the vaccination of a rabbit against twenty lethal doses. In six months we can succeed in making it very easily withstand 100 lethal doses. The serum of rabbits thus treated soon, i.e., after they have received from five to six lethal doses, exhibits antitoxic properties tn vitro ; these, however, are not very pronounced until after prolonged treatment. They gradually become just as intense as those observed in the case of animals vaccinated against diphtheria or tetanus. In 1895 Fraser confirmed these results,^ and on May 15 in that year exhibited before the Medico-Chirurgical Society of Edinburgh a rabbit vaccinated against a dose of cobra-venom fifty times lethal. At once considering the possibility of obtaining serums highly antitoxic against snake- venoms, and of practical utihty in the thera- peutics of snake-bites, I prepared to vaccinate a certain number of large animals, horses and donkeys, in order to procure great quan- tities of active serum. I at first experienced some difficulties in providing myself with a sufficient store of venom. But thanks on the one hand to the obliging collaboration of some of my old pupils ' British Medical Journal, June 15, 1895. 244 VENOMS or colleagues, and on the other to the valuable co-operation of the Colonial Governments of Indo-China, the French Settlements in India, and Martinique, I soon received poisonous snakes and dried venom in abundance. After this I was not long in pushing the vaccination of a few horses until I made them resist, in a single injection, 2 grammes of dry cobra-venom, a dose about eiglity times lethal; for I was able to satisf)^ myself that about 0-025 gramme of cobra-venom was sufficient to kill fresh horses in from twelve to twenty-four hours. The immunisation of horses to this very high degree of tolerance of venom is not obtained without difficulties; many animals sue- VACCINATION AGAINST SNAKE-VENOM 245 cuinb in course of treatment from endocarditis or acute nephritis ; in the case of others, each injection of venom leads to the forma- tion of enormous aseptic abscesses, which have to be opened and drained. It may be said that on an average an interval of sixteoijnonths is necessary in order to obtain a serum sufficiently antitoxic. Fig. 94. — Aseptically Bleedikg a Hoese Vaccinated agaisst Venom in oedeb TO OBTAIN AntIVENOMOUS SeEUM AT THE PaSTEUE INSTITUTE AT LiLLE. When a horse is v^ell vaccinated and tolerates v^'ithout a reaction 2 grammes of fdry cobra-venom in a single subcutaneous injection, it may be bled on three consecutive occasions °in the space of ten days, and in this way 20 litres of blood may be drawn from it (fig. 94). ■ 246 VENOMS The bleeding is avranged in the following manner : Twelve days after the last injection of venom the horse is bled for the first time to the extent of 8 litres ; five days later it is bled for the second time to the extent of G litres ; five days later still the third bleeding takes place, v^^hen G litres are again withdrawn. The animal is then allowed to rest for three months and sup- plied with strengthening food, and during this period 2 grammes of venom are again injected on two occasions at the end of a month, followed, a month and a half later, by the injection of 2 more grammes. The antitoxic power of the serum is thus maintained approximately at the same standard. The serum drawn off at each bleeding must be severely tested, which is done by gauging its antitoxic power in vitro, when mixed with venom, and also its preventive effect. An antivenomous serum may be considered to be utilisable when a mixture of 1 c.c. of seram with 0 -001 gramme of cobra- venom produces no intoxicating effect in the rabbit, and when a preventive sabcutaneous injection of 2 c.c. of serum into a rabbit of about 2 kilogrammes enables it to resist, two hours later, sub- cutaneous inoculation with 1 milligramme of venom. The preventive power may be very quickly tested by injecting a rabbit, in the marginal vein of the right ear for example, with 2 c.c. of serum, and injecting, five minutes afterwards, in the marginal vein of the left ear, 8 milligramme of venom. This dose of 1 milligramme generally kills the control rabbits in less than thirty minutes when introduced into the veins, and in from two to three hours when injected beneath the skin. This rapid proof by intravenous injection is extremely striking and demonstrative ; it can be effected in public during a class or lecture in less than an hour, and enables an immediate estimate to be formed of the value of an antivenomous serum. When it is intended to adopt this method, it is essential to make use of a recent solution of venom, for solutions from a week to a fort- night old, although sterile, have already lost a large portion of VACCINATION AGAINST SNAKE-VENOM 247 their toxicity, and, if these be employed, the dose of venom calculated to kill the control animals in thirty minutes, for example, takes an hour or more to do so. I always prepare my test solutions of venom in the following manner : — Ten milligrammes of dry cobra-venom are weighed in a delicate balance. The venom is dissolved in 10 c.c. of 0-8 per cent, physio- logical salt solution, which takes a few minutes. When the venom is thoroughly dissolved it is transferred to a test-tube, which is immersed for three-quarters of an hour in a water-bath heated to -f- 72° C. In this way the non-toxic albumins are coagulated without modifying the neurotoxic substance. The solution is poured on to a filter of sterilised paper, and the clear liquid which is collected is immediately put up in glass phials, which are hermetically sealed, or in small sterilised bofctlos. Its toxicity is tested upon control animals, and it may be kept for five or six days if protected from light, or for several weeks in a refrigerator at about 0° C. One-tenth of this solution corresponds exactly to 1 milligramme of dry venom.. As for the antivenomous serum, as soon as its antitoxic value has been ascertained by the methods that I have just described, and it has been separated from clots and red corpuscles by suitable decantation, it is portioned out, with the usual aseptic pre- cautions, into small sterilised bottles of 10 c.c. capacity, without the addition of any antiseptic. In order to ensure that it will keep for a long time, care is then taken to heat the hermetically sealed bottles in a water-bath af a temperature of 58° C. for one hour, and this operation is repeated for three days in succession. Serum prepared in this way preserves its antitoxic power unimpaired' for about two years, in all climates. I have had occasion at various times to receive bottles which had been sent eighteen months and two years previously to India and Indo-China, VENOMii and I was able to show that their standard had not perceptibly deteriorated. It was only the appearance of the contained liquid that was slightly changed; it was discoloured, and when shaken small white flakes were seen floating through it. These flakes are not a sign of deterioration ; they are composed of deposits of precipitated albumin. They can be partly dissolved again by violent shaking, or they may be separated before use by filtration through sterilised paper. In a dry state, antivenomous serum may be kept for an almost indefinite period, in hermetically sealed glass tubes. In this con- dition it is usually divided into doses of 1 gramme, and when it IS desired to make use of it, it is sufficient to dissolve a dose in 10 c.c. of water which has been boiled and allowed to cool, which takes two or three minutes. This solution is then injected beneath the skin, as though it were liquid serum. The Pasteur Institute at Lille prepares in this way large quantities of antivenomous serum, which are sent all over the world to those countries in which poisonous snakes are most dangerous. Eecently, special laboratories for the production of this prepara- tion have been instituted at Bombay and at Kasauli, in the Punjab, by Drs. G. Lamb and Semple ; at Philadelphia, by Professor McFarland ; at Suo-Paulo, in Brazil, by Dr. Vital Brazil ; and at Sydney, by Dr. Tidswell. Specificihj and Pohjvale^ice of Antivenomous Serums.— By means of a large number of experiments I have proved that snake-venoms, whatever their origin, contain two principal substances: neuro- toxin, which exerts its effects upon the elements of the nervous system, and Immorrhagin (Flexner and Noguchi), or proteolytic diastase, the effects of which remain exclusively local when the venom is introduced subcutaneously into the cellular tissue, but which produces coagulation of the blood when the venom is n;ctei directly into the blood -stream, VACCINATION AGAINST SNAKE-VENOM 249 The venom of CoLUBRiDiE in general is characterised by the constant predominence of neurotoxin, to which it owes its extreme toxicity, which is especially intense in the case of cobra-venom. It contains no, or scarcely any, licemorrhagin ; for this reason the local symptoms of poisoning by Colubrine venom are almost nil. This neurotoxin, as we have seen, shows itself very highly resistant to heat. The venom of Vipbrid^, on the contrary, especially that of Lachesis, is characterised by the almost total absence of neuro- toxin, while its richness in JicBmorrhagin is considerable. Con- sequently, heating for a few minutes at + 75° C. renders it almost entirely inactive, since JicBmorrhagin is very sensitive to heat. Griven venom of some kind or other, the origin of which is unknown, it is therefore possible to ascertain whether the snake from which it was extracted belonged to the CoLUBUiD^ or ViPERiD^, by determining its richness in neurotoxin resistant to heating at + 85'' C. Certain Vipbrhste venorns, such as those of the European Viper a her us and Vipera asp is, the African Cerastes and American Crotalus contain at the same time a small proportion— varying greatly in amount according to the species — of neurotoxin, and a much larger proportion of Immorrhagin. It is for this reason that these venoms, although greatly attenuated and deprived of their local action by heating, still remain toxic when injected in large doses into animals after having been heated to + 75° C. On the other hand, some Colubrine venoms, such as those of Bungarus ccendeus, which are very rich in neurotoxin, contain a quantity of hsemorrhagin sufficient to differentiate their effects in appearance from those produced by cobra-venom, when they are injected, not beneath the skin, but directly into the veins. In this case their effects upon the blood are added to those of their neurotoxin. It would seem, too, that the venoms of Australian Colubrid^ 250 VHNOMS (Hoplocephalus, Pseiidechis) form a special group, which is richer in licemorrliaqin than are those of the Colubrid^ of the Old World. ^ On studying, in the case qf these various venoms, the action in vitro and in vivo of a purely antineurotoxic antivenomous serum, such as, for example, that of an animal vaccinated against cobra- venom heated to + 75° C, it is found that this serum has a very decided effect upon cobra-venom, and likewise upon that of snakes belonging to allied species (Naja bungarus, Naja haje), and that its action upon the other venoms is less in proportion as they contain less neurotoxin. It prevents haemolysis in vitro, and suppresses the effects of intoxication on the nervous system, but does not modify in any way the phenomena of coagulation or of proteolysis. If this serum be made to act in vitro on those Viperine venoms that, when heated to -|- 75° C. and deprived of their hsemorrhagin, remain neurotoxic, like the venom of the common viper, it is found that it renders them entirely innocuous. There- fore, in the case of all species of poisonous snakes, and perhaps also in that of other poisonous animals (such as scorpions), it appears that the neurotoxic substance is one and the same, and always neufcralisable by an antineurotoxic serum like that of animals vaccinated against cobra-venom. Neurotoxin being the essentially active substance in venoms, and that to which the dangerous properties of poisonous snakes, as regards man and domestic animals, are especially due, it is the effects of this that it is most necessary to prevent. Consequently, ' Cf. papers by George Lamb, Scientific Memoirs by Officers of the Medical and Sanitary Departments of the Government of India, New Series, Nos. 1, 3, 4, 5, 7, 10, 16 ; L. Eogers, Froceedinffs of the Boyal Society of London, vol. Jxxii., and Lancet, February 6, 1904; C. J. Martin, Intercolonial Medical Journal of Australasia, August 20, 1897, April 20, 1898 ; Dr. Hunter, Lancet, January 2, 1904; Dr. TidswcU, Australasian Medical Gazette, April 21, 1902; A. Cahnette, Comi^tes rendus de V Academic des Sciences, May 2, 1904 ; Dr. Vital Brazil, "Contribution a I'etude de Tintoxication ophidienne " (separately published pamphlet), Paris, 1905 ; G. Bill, Intercolonial Medical Journal of Australasia, July 20, 1902. VACCINATION AGAINST SNAKE-VENOM 251 the -first quality that an antivenomoas serain ought to exhibit, in order to be capable of being used in the therapeutics of poisoning, is the possession of an antineurotoxic power as high as possible. This antineurotoxic power is easily obtained by employing cobra-venom for the fundamental immunisation of the horses destined for the production of the serum. Antineurotoxic serum thus prepared shows itself perfectly capable of preventing all effects of intoxication from cobra-bites, which are much the most frequent in India. In the same way it shows itself quite sufficiently efficacious with regard to CoLU- BRiNE and ViPERiNE venoms, the neurotoxic activity of which may cause death. But it does not possess any preventive action upon the local effects of hcpmorrhagin, to which the noxiousness of certain Vipbeine venoms — such as those of Lachesis — are almost exclusively due. In countries in which Viebrid^ are very common, we must therefore not confine ourselves to vaccinating the animals that produce serum solely against the neiwotoxin of cobra-venom, for instance ; we must prepare these ai)imals, after having immunised them to cobra-venom, by injecting them with progressively increas- ing doses of the various venoms derived from the snakes that are most frequently met with in the district. Nothing, moreover, is easier than to train animals vaccinated against cobra-venom to tolerate strong doses of the venoms of Lachesis, Vipera riissellii, Crotalus, Hoplocephalus , or Pseudechis. In a few months we succeed in obtaining serums very active against these different venoms. Utilising the horse as producer of antitoxin, I have prepared by this method polyvalent serums capable of preventing the local action of Viperine venoms, and of suppressing in vitro their coagulant and proteolytic effects upon the blood. Unfortunately, great as has been the kindness of the many persons who have most obligingly given me their assistance in the course of the fifteen years during which I have studied this ques- 252 VENOMS tion, I have found it impossible to procure sufficient quantities of venoms of various origins to furnish each country with the poly- valent serums corresponding to its particular needs. I have there- fore been obliged to confine myself to preparing for the most part antineurotoxins, which I have been able to do, thanks to the abundant provision of Cobra- and Bungarus-venoms, for which I am indebted to the liberality of the Government of the French Settle- ments in India, and to that of my pupils and friends who are at the present time in charge of the Colonial Laboratories of Indo-China. Moreover, the recent foundation of the Serum-Therapic Institutes of Bombay and Kasauli, Sydney, Sao-Paulo, and Philadelphia, to-day renders it very easy for each country to provide itself with antivenomous serum, either specific or polyvalent. Other institutes will doubtless be established for the purpose of extending the bene- fits of a method, the efficacy of which is sufficiently evident for its adoption to be incumbent upon all those who are concerned with safeguarding human existence. 253 CHAPTER XIV. NEVTBALISATION OF VENOM BY ANTITOXIN. It is difficult, in the present state of our knowledge on the subject of toxins and antitoxins, to determine the precise nature of the reactions that are produced in the living organism as the result of serum injected for the purpose of preventing the toxic action of venom. I maintained, some years ago/ that the phenomenon in this case was a purely physiological one, which I considered to be proved by the fact that, if we mix in vitro, in determinate propor- tions, venom and antivenomous serum, and if we heat this mixture at 68^ C. for half an hour, the injection of the heated mixture kiUs animals as if they were inoculated with venom alone, although with a considerable retardation. I concluded from this that, in all probabihty, antitoxic serum does not modify the toxin with which it is mixed, but that it confines itself to displaying a parallel and opposite action by preventing the noxious effects. I therefore supposed that no chemical combination is produced between these two substances, or, at least, that the combination effected is very unstable. My experiments were subsequently repeated by Martin and Cherry,^ who showed that the results as stated above were perfectly correct when the mixture of venom and antitoxin was heated less than ten minutes after it had been made, but that, if the heating ' Annales cle VInstitut Pasteur, 1895, No. 4. " The Nature of the Antagonism between Toxins and Antitoxins," Proceed- ings of the Boyal Society of London, vol. Ixiii., 1898, p. 420. 254 VENOMS did not take place until twenty or thirty mimitcs later, the toxicity of the venom no longer reappeared. On the other hand, the admirable researches of Kyes and Sachs, and subsequently those of Morgenroth, pursued under the direction of Ehrlich at the Laboratory of Experimental Tlierapy at Frank- fort, have proved the readiness of venom to enter into chemical combination with certain elements of normal serums, in particular with lecithin, a combination which results in the formation of Immolysing and non-toxic lecithides, the neurotoxin being left free. It therefore seemed impossible to deny the existence of a chemical reaction between the venom and the serum, which was until quite recently considered as proved. We shall see presently that this is not the case. But let us first endeavour to determine the laws that govern the neutralisation of variable quantities of venom by antivenomous serum. If, in a series of test-tubes, we bring the same quantity of cobra- venom {e.g., 0-00005 gramme, a dose which is invariably lethal to the mouse in two hours) into contact with progressively increasing quantities of an antivenomous serum (e.g., 0 01 c.c, 0-02 c.c, &c., up to 01 c.c), and, after thirty minutes of contact, inject these different mixtures subcutaneously into a series of mice, we find that all those that have received the mixtures containing less than 0-05 c.c. of serum succumb after variable intervals, while all the rest survive. It is evident that, under these conditions, the serum experi- mented upon has shown itself capable of neutrahsing in vitro, in a dose of 0 05 cc, 5 ceutimilligrammes of venom. The same serum should therefore neutralise 1 milligramme of venom in a dose of 1 c.c, that is to say, that this mixture injected into a mouse ought to be entirely innocuous. Experiments show, however, that in reahty it is necessary to mix 1-2 c.c. of serum with 1 milligramme of venom in order that the inoculated mouse may not succumb; This proves that, in the initial mixture of 0-C0005 giamme of venom + 0 05 c.c. of serum, there remained an exceedingly small NEUTBALISATION OF VENOM BY ANTITOXIN 255 quantity of non-neutralised venom, and that this quantity of venom in a free state was insufficient to cause the death of the animal, or even any apparent malaise. When multiplied by twenty, however, it becomes capable of producing toxic effects; it is for this reason that, when it is desired to inoculate a mouse with twenty times the lethal dose of 0*00005 gramme neutralised, it is necessary to mix ■ with this twenty times lethal dose a dose of serum a little large?- than twenty times that which renders O'OOOOS gramme of venom innocuous to the mouse, that is to say, 1'2 c.c. If, instead of making use of the mouse ,as test animal, we employ the rabbit, it is found that the same serum, in a dose of 0-75 c.c, neutralises O'OOl gramme of venom sufficiently for the mixture to be innocuous when inoculated. It is clear that, in this mixture, the whole of the venom was not neutralised by the serum, but the small quantity left free is incapable of producing harmful effects. By this method of employing mixtures of the same dose of venom with variable quantities of antivenomous serum, we are therefore enabled to determine with the greatest exactness the antitoxic power in vitro of each specimen of serum. But it must not be forgotten that the resiilt obtained applies only to the species of animal into lohich the mixtures toere injected. I have already stated (Chapter YIII.) that a fairly close paral- lelism exists between the neurotoxic action of venoms and their hemolytic action, and I have established that, in order that the sensitive red blood-corpuscles may be dissolved under the influence of venom, it is indispensable that the reaction take place in the presence of normal serum, since venoms have no effect upon red corpuscles freed from serum by several successive washings and centrifugings. Preston Kyes has explained this phenomenon very well by showing that the venom combines with the lecithins in the serum, or with those contained in the stroma of the corpuscle, so as to constitute a hasmolysing lecithide. The knowledge of this fact enables us to determine, by means 256 VENOMS of a very neat and simple methocl, and with a sufficient degree of accuracy for practical purposes, the antitoxic power of an anti- venomous serum by measuring its antihcemolytic power.' To this end it is sufficient to cause variable doses of serum to act on a given quantity of defibrinated horse- or rat-blood, to which a constant dose of venom is then added. We employ, for example, a 5 per cent, dilution of defibrinated horse-blood, which is portioned out in doses of 1 c.c. into a series of test-tubes. To each of these tubes in succession is added a progressively increasing quantity of the serum for titration, starting with 0-01 c.c, and continuing with 0-02 c.c, 0-03 c.c, &c, up to 01 c.c A control tube receives no serum. There are then introduced into all the tubes 1 decimilligramme of venom and 0-2 c.c of normal horse-serum, deprived of alexin by previous heating for half an hour at 58° C. At a temperature of about 16° C. .haemolysis commences to manifest itself in the control tube in from fifteen to twenty minutes. It takes place in the other tubes with a retardation which varies with the dose of serum added. Tubes are to be noticed in which it does not occur even after the lapse of a couple of hours. Experience shows that we may consider as good for theraj)eutic use' serums which, in a dose of 0'05 c.c, completely prevent haemo- lysis by 1 decimilligramme of Colubeine venom, such as that of Cobra, Krait, &c., and those that in a dose of O'T c.c, prevent haemolysis by 1 milligramme of the venom of Lachesis or Vipera herus. By a method calculated upon the foregoing, it is likewise possible to measure the antihamorrliagic activity of an anti- venomous serum, for the parallelism existing between the anti- neurotoxic and antihamolytic actions of serums occurs again, as I have been able to establish in conjunction with Noc, between the antihcBViorrhagic and antiproteolytic action of the same serums. ' Calmette, Co^JijJfes rendus de VAcadeviie des Sciences, 1902, No. 24 ; Preston Kyes, Berliner klinische Wochenschrift, 1904, No. 19. NEUTBALISATION OF VENOM BY ANTITOXIN 257 Now, the antiproteolytic action is easily determined by means of a series of test-tubes containing the same quantity of 20 per cent, gelatinised bouillon, rendered imputrescible by the addition of a small quantity of thymol. The gelatine being kept liquid in the incubating stove, a progressively increasing quantity of serum is poured into each tube. The same dose of venom, say 1 milli- gramme, is then added in each case. The tubes are placed in the stove for six hours at 86° C. They are then v^^ithdravs^n and immersed in a bath of cold water. Those in v^hich the gelatine solidifies are noted, and thus w^e establish the dose of antivenomous serum that inhibits the proteolysis of this substance. These different methods of control enable us to verify the activity of antivenomous serums with great exactness, without the necessity of having recourse to experiments upon animals. In a very important memoir on the reconstitution of the toxins from a mixture of toxin + antitoxin, J. Morgenroth ^ has shown that the venom, after being naturalised by the antivenomous serum, can be dissociated from its combination by means of a method which consists in adding to the latter a small quantity of hydrochloric acid. Previous experiments by Kyes had established : — (1) That antivenomous serum, the antitoxic action of which is so manifest when it is mixed in vitro with cobra-venom, remains entirely inert when brought into contact with the combination lecithin -f venom, that is to say, with cobra-lecithide. (2) That the addition of lecithin to a neutral combination of veno7n + antivenomous serum does not set the venom free again, and that under these conditions no lecithide is formed. If, in a neutral mixture of cohra-hmmolysin and antitoxin we could succeed in dissociating the two constituent elements, and in then making the cohra-hcemolijsin combine with the lecithin, ' Berliner IcUnische Wochenschrift, 1905, No. 50. 17 258 VENOMS we should have a toxin and antitoxin side by side ; for the reasons indicated above, this toxin {Iccithide) and antitoxin {anti- venomous serum) would be no longer capable of combining ; but the toxin {lecithide) , thanks to its hemolytic properties, could easily be demonstrated. It is precisely this desideratum that J. Morgenroth has suc- ceeded in realising, by means of hydrochloric acid, which renders it possible to dissociate the neutral mixture, toxin + antitoxin, into its constituent elements, and then to obtain a lecithide. Experiments show that the quantity of lecithide thus restored absolutely corresponds to that of the cobra-hsemolysin originally added to the antitoxin, and that the antitoxin set free is not injured by the hydrochloric acid, even after twenty-four hom-s of contact. It is sufficient to add the quantity of soda or of ammonia necessary for the neutralisation of the acid, in order to see the antitoxin reappear in its original strength. It is therefore possible, by causing hydrochloric acid (in a solution not stronger than 3 per cent.) to act on a neutral mixture of cobra-hffimolysin (toxin) and antitoxin, to set the former at liberty in the form of lecithide, to withdraw the latter from the action of the antitoxin, and to demonstrate its presence, owing to its haemolytic properties. It has been found by Kyes and Sachs that, under the influence of hydrochloric acid, cobra-hasmolysin becomes resistant to heat to such an extent that it is not destroyed even by prolonged heating at 100° C. If to a neutral mixture of toxin 4- antitoxin we add a small quantity of hydrochloric acid, and then heat the mixture at 100° C, the antitoxin being in this case destroyed, we shall recover the whole of the toxin originally employed. Therefore, as was shown by me so long ago as 1894, if the mixture of toxin + antitoxin produces a chemical combination between the two substances, this combination is unstable, and can be effectively broken up into these two constituent elements by various influences. 259 CHAPTEE XV. TREATMENT OF POISONOUS SNAKE-BITES IN MAN AND ANIMALS. OBJECTS OF THE TREATMENT : TECHNIQUE OF ANTIVENOMOUS SEBUM-THEBAPY. In all countries the remedies recommended for the bites of poisonous snakes are innumerable, and native pharmacopoeias abound in so-called infallible recipes. Pliny himself wrote on this subject as follows : — - " For poisonous bites, it is customary to employ a liniment made of fresh sheep-droppings, cooked in wine. Rats cut in two are also applied ; these animals possess important properties, especially at the epoch of the ascension of the stars, seeing that the number of a rat's fibres wax and wane with the moon. " Of all birds, those that afford most assistance against snakes are vultures. The black ones are the weaker. The odour of their feathers when burnt puts snakes to flight. Provided with a vulture's heart one need not fear encounters with snakes, and can also defy the wrath of wild beasts, robbers, and princes. " Cock's flesh, applied while still warm, neutralises the venom of snakes. The brains of the bird, swallowed in wine, produce the same effect. The Parthians, for this purpose, make use of chicken's brains. The fresh flesh of the pigeon and the swallow, and owls' feet burned, are good against snake-bites. " If one has been bitten by a snake or by any venomous animal, another method of cure is to take salt fish and wine from time to time, so as to vomit in the evening. This remedy is chiefly 260 VENOMS efficacious against the bite of the Chalcis, Cerastes, Seps, Elaps and Dipsas.'' In Equatorial America, and especially in India, a multitude of plants are credited with marvellous properties, which they possess only in the imagination of the snake-charmers or medicine- men by whom they are employed. None of them stand the test of experiment, any more than the more or less compound drugs, numbers of specimens of which from all sources have passed through my hands. It cannot, however, be denied that certain chemical substances, of well-defined composition, are very useful, not as physiological antidotes to venoms, but as agents for their modification or destruc- tion in the poisoned wounds, when they have not yet been absorbed. In this way permanganate of potash, chromic acid, chloride of gold, and the alkaline hypochlorites, especially hypocldorite of lime, may be extremely useful under many circumstances. Permanganate of potash was recommended in 1881 by Professor de Lacerda,^ of Eio de Janeiro, as the result of experiments made by him with venoms of Brazilian snakes. When a few cubic centimetres of a 1 per cent, solution of permanganate of potash are quickly injected into the actual wound caused by the bite and around the point of inoculation, there can be no doubt that the venom not yet absorbed is destroyed. When mixed in vitro with venom, permanganate renders the latter innocuous. Here, however, it is a case of actual destruction by direct contact. If we inject a lethal dose of venom into the right thigh of an animal, for example, and several cubic centimetres of per- manganate solution into different parts of the body, or beneath the skin of the left thigh, neither the general intoxication nor the local effects of the venom are modified. The same may be said with regard to chromic acid (1 per cent. ' Com;pte8 rendus de VAcademie des Sciences, Paris, September, 1881. TREATMENT OF POISONOUS SNAKE-BITES 261 solution), recommended by Kaufnaann^ for the bite of the common viper. No other effect is produced by a 1 per cent, solution of chloride of gold, or the alkaline liypoclilorites, which I have shown to possess a strong oxidising action on the different venoms, even on those that are most rapidly diffusible, such as cobra-venom (see Chapter V.). They possess, however, owing to their slight causti- city, the advantage of not producing severe local disorders, and in this respect they are to be preferred. The chemical reagent most to be recommended is hijpochlorite of lime, in a fresh solution of 2 grammes per cent., and containing about 90 c.c. of chlorine per 100 grammes. It immediately and surely destroys the venom by simple contact, and the chlorine gas that it gives off, owing to its great diffusibility, acts at a fairly long distance from the point of inoculation on the venom which is already beginning to be absorbed. Professor Halford, of Melbourne, advises the direct injection into the patient's veins of from 10 to 20 drops of ammonia, diluted with an equal quantity of distilled water. This is a means of reviving nervous excitabiHty in certain subjects at the commence- ment of intoxication; but torpor soon reappears, and, if the dose of venom inoculated is sufficient to cause death, a fatal ending takes place notwithstanding. Experimentally the effects of ammonia are nil. No better results are obtained by injections of strychnine, as recommended by Dr. Mueller, in Australia. Moreover, the statistics published by Easton Huxtable^ positively condemn this therapeutic method. They show that, in 426 cases of snake-bite, out of 113 treated by strychnine 15 proved fatal, the ratio of mortahty being 13-2 per cent., while the 313 cases not treated by strychnine only resulted in 13 deaths, or a mortahty of 41 per cent. ' " Lo venin de la vipere," Paris, 1889. ^ Transactions of the Third Intercolonial Congress, 1892, p. 152. 262 VENOMS In the case of animals intoxicated by venom, injections of strychnine, morphia, nicotine, or curare in small doses always prove ineffective ; they even considerably assist the progress of the intoxication and hasten death. The use of these drugs in the case of human beings should therefore be absolutely forbidden. It appears, on the other hand, that alcohol and coffee, or tea, absorbed by ingestion, are very often beneficial. Indeed, it was long ago observed that the swallowing of alcohol until symptoms of drunkenness appear retards or diminishes the phenomena of torpor and paresis that precede the ultimate phase of the intoxica- tion. Its use may therefore be recommended when it is impossible to have recourse to the only treatment really specific that modern science places in our hands — antivenomoiis serum-therapy . It is important, however, to state that, lolien serum is used, alcohol must be forbidden. The latter hinders the effects of the former. In practice, the rational treatment of the bite of a venomous snake must be directed towards : — (1) Preventing the absorption of the venom. (2) Neutralising, by the injection of a sufficient quantity of antitoxic serum, the effects of the venom already absorbed. In order to prevent the absorption of the venom introduced into the wound, the first precaution to be taken is to compress the bitten limb by means of a ligature of some kind, such as a handkerchief, as close as possible to the bite, and between it and the base of the limb. The ligature must be tightly twisted, and, by compressing the tissues around the bite, an attempt should be made to squeeze out the venom that may have been introduced into them. The expulsion of the poison should be hastened, either by making an incision 2 or 3 cm. in length and 1 cm. in depth in the direction taken by the fangs of the reptile and also parallel to the axis of the bitten member, or by sucking the wound hard. The ligature on the limb should not be apphed for more than half an hour ; if it v^ere kept on longer it would interfere with the circulation to a dangerous degree, and would certainly injure the TREATMENT OF POISONOUS SNAKE-BITES 268 vitality of the tissues. The period in question also usually affords sufHcieut time for taking the patient to a place where help can be obtained, and for the preparation of everything necessary for his subsequent treatment. The wound should then be freely washed with a fresh 2 per cent. solution of hypochlorite of lime, or with a 1 in 1,000 solution of chloride of gold. In default of hypochlorite of lime or chloride of gold, either eau de Javel, diluted with tepid water to a strength of 1 in 10, or a 1 per cent, solution of permanganate of potash, may be employed. These reagents should be made to penetrate as deeply as possible into the tissues, and a few cubic centimetres of them should even be injected with a Pravaz syringe into the punctures caused by the bite and all round them. The wound being then covered with a damp dressing by means of compresses saturated with hypochlorite of lime, or at least with pure alcohol, the next thing to be done is to prepare to apply the serum- thexapic treatment in order to arrest the general intoxication, if this has already commenced to take effect, or to prevent it from setting in. For the employment of serum it is necessary to be in possession of a sterilisable syringe of the capacity of 10 c.c, similar to those used in the treatment of diphtheria. If the life of the patient be not immediately in danger, care should first be taken to have the syringe boiled, or at least to rinse it out with boiling water, making sure that the piston fits tightly, and that the syringe itself is in good working order. Should a syringe of 10 c.c. not be available, any kind of Pravaz syringe, previously washed out with boiling water, may be em- ployed, but in this case the use of so small an instrument renders it necessary to give several painful injections. The entire contents of a bottle of serum (10 c.c. of liquid serum, or 1 gramme of dry serum dissolved in 10 c.c. of boiled water) should be injected into the subcutaneous areolar tissue of the abdomen, on the right or left side. There is no advantage in 264 VENOMS making the injection at the actual spot bitten ; the serum is best and most rapidly absorbed when injected into the loose tissues of the abdominal wall (fig. 95). Fig. 95. — Technique of the Injection of Antivenomous Serum beneath the Skin of the Abdomen. If it has been impossible to apply the treatment mitil several hours after the bite, and if the latter has been inflicted by a poisonous snake of large size or belonging to a very dangerous TREATMENT OF POISONOUS SNAKE-BITES 265 species, such as the Cobra or Indian Kuait, it is preferable to inject into the patient three whole closes of serum at once. In cases in which the phenomena of serious intoxication have already appeared, and when asphyxia threatens, one must not hesitate to inject 10 or even 20 c.c. of serum directly into a vein. For such an injection it is most convenient to choose a superficial vein at the elbow or wrist, or on the back of the hand. The introduction of serum into the veins is never dangerous if good care be taken not to allow either bubbles of air or particles of precipitated albumin to enter. It is not advisable to repeat the injections beneath the skin or into the veins unless the general symptoms appear to become more acute. In most cases the local pain, excitement, and attacks of cramp and nausea disappear within a few minutes after the first injection. Improvement progresses very rapidly, and by the following day the patient has recovered. The administration of ammonia, alcohol, morphia, or ether by the mouth is entirely superfluous. These drugs, as I have already stated, may even be harmful to the patient and hinder the. effects of the serum. All that should be done is to give copious hot drinks, tea or coffee, and to cover up the patient warmly in order to induce abundant perspiration. The bitten member should not be cauterised with red hot iron or with chemical agents of any kind, since such cauterisations only lead to injuries which are too often prejudicial to the normal action of the affected organs. Treatment of Poisonous Bites in the Case of Domestic Animals. — It often happens .that dogs, horses, or cattle are bitten and succumb to the poisoning in a few hours or in two or three days. Such accidents are especially frequent among sporting dogs, even in Europe, in regions in which vipers are found. In most cases, dogs, horses, and cattle are bitten on the nose, and such bites are immediately followed by a very painful swelling, 266 VENOMS which arouses the suspicion of the owners of the animals. It is then necessary, as soon as possible, to inject subcutaneously in the right or left flank, or at the base of the neck, one or two doses of antivenomous serum, according to the gravity of the effects observed. The injection of the serum and the dressing of the wound should be performed as in the case of poisonous bites in human beings. Infl,uence of the Doses of Antivenomous Serum injected, and of the Time that has elapsed shice the Venomous Bite. — I have stated above that antivenomous serum possesses a preventive and curative power of such intensity, that it is capable in a few minutes of rendering animals into which it has been injected absolutely in- sensible to the most strongly neurotoxic venoms, such as those of Naja or Bungarus. On the other hand, I have established the fact that, the more sensitive are the animals to intoxication by venom, the greater is the quantity of antivenomous serum necessary to immunise them passively or to cure them. In experimenting upon mice, guinea-pigs, and rabbits, it is found that in order to preserve, let us say, a mouse of 25 grammes against inoculation with half a milligramme of venom, which is ten times the lethal dose for this little animal, it is necessary to give a preventive injection of 1 c.c. of serum ; while half a cubic centimetre of the same serum is sufficient to render the dose of half a milligramme of venom innocuous, when venom and serum are mixed in vitro before being injected. In the case of the guinea-pig, it is likewise found that the dose of serum to be injected preventively, in order to protect the animal from intoxication by ten times the lethal dose of venom, is about tivice as much as the quantity of the same serum that it is sufficient to mix iji vitro with venom, in order to render ten times the lethal dose of venom innocuous. If we inject into animals first venom, in doses calculated to kill the controls of the same weight in from two to three hours, and the serum fifteen minutes afterwards, it is found that the TBEATMENT OF POISONOUS SNAKE-BITES 267 quantity of serum that must be injected in order to prevent death is abont thrice as great as that which neutrahses in vitro the dose of venom inoculated. It is also found that the amount of curative sermn that an animal intoxicated by venom must receive is inversely proportional to its loeight. The experiments upon dogs, performed at the Pasteur Institute at Lille by my collaborator G. Gu6rin, are highly demonstrative in this respect.^ A dog of 12 kilogrammes, inoculated with 9 miUigrammes of venom (a dose lethal to controls of the same weight in from five to seven hours), is completely cured on receiving, two hours after inoculation ivith the poison, 10 c.c. of serum. When the treatment does not take place until three hours after the injection of the venom, it is necessary to inject 20 cc. of serum in order to prevent the animal from dying. With a longer delay than this, death is inevitable, since the bulbar centres are already affected, and paralysis of the respiratory muscles commences to appear. These facts show that : — (1) The more sensitive animals are to venom, the greater is the quantity of serum necessary in order to prevent their intoxication by a given dose of venom. (2) For a given species of animal and a given dose of venom, the longer the delay in applying the remedy, the greater is the quantity of serum that must be injected in order to arrest the p)oisoning. It will be understood from what has been already stated, that a man weighing 60 kilogrammes, if bitten by a snake which injects, let us say, what would amount to 20 milligrammes of venom if collected in the dry state (the mean quantity that a I " Les morsures de viperes cliez les animaux," Becueil de medecine veteri- naire d'Alforl, May 15, 1897. 268 VENOMS Naja is able to inoculate in a single bite), would only require, in order to escape death, to receive the quantity of antivenomous serum sufficient to neutralise the portion of venom in excess of the amount that he could tolerate without dying. Let us suppose, for the sake of example, that the man of GO kilogrammes can withstand intoxication by 14 milligrammes of Naja-yenom. It follows that, in the case with which we are dealing, we must inject sufficient serum to neutrahse 20—14 ( = 6) milligrammes of venom ; that is to say, the injection of serum being made immediately after the bite, 6 c.c, if the serum employed neutralises in vitro 1 milligramme of venom per cubic centimetre. Of course, if the serum is more powerful, less of it will be necessary, while more will be required if the remedy is apphed later, or if the quantity of venom inoculated by the snake is supposed to have been greater. Por this reason, in practice, but very little serum is usually necessary in order to augment the natural resistance of a man of average weight or of a large animal ; it is sufficient in most cases to give' an injection of 10 or 20 c.c. in order to cure human beings who have been bitten. The chnical proof of this is, more- over, to be found in the cases, already very numerous, that have been published in the course of the last few years in the scientific journals of all countries. I have gathered together a few of these in the concluding pages of this book, and I would beg the reader to be good enough to refer to them. 269 PART IV. VENOMS IN THE ANIMAL SEMES. CHAPTER XVI. l.—INVEBTEBBATES. Besides reptiles, many other animals possess poison-glands and inoculatory organs which they employ, either to defend them^ selves against their natural enemies, or to capture the living prey upon which they feed. The venoms that they produce are still, for the most part, but little understood. A few of them, however, have excited the curiosity of physiologists, especially those secreted by certain batrachians, such as the Toad, and certain fishes, such as the Weever. Some of them exhibit close affinity to snake-venom, and are composed, like the latter, of proteic substances modifiable by heat and precipitable by alcohol ; others possess altogether special characters, and resemble alkaloids. The lowest animal group in which these secretions begin to be clearly differentiated is that of the Goelenterates. A. — Goelenterates. It has been shown by Charles Eichet^ that the tentacles of sea- anemones {Anemone scultata) contain a toxic substance which has ' Comptes rendus de la Socieie de Biologic, December 13, 1902 ; June 6, July 25, 1903; February 20, 1904. 270 VENOMS the curious property of causing intense itching, pruritus, and even urticaria. Tliis poison is perfectly soluble in alcohol, and can be prepared in the following manner : — The tentacles are cut off close to the body of the animal, and immersed for a few days in an equal weight of alcohol at 95° C. The red liquid that results is decanted, and then filtered. The msoluble material is compressed, and yields large quantities of fluid, which is filtered and mixed with the previous liquid. The whole is then evaporated in vacuo until there remains a thick oily liquid, which forms a red deposit. Filtration through paper is again employed, in order to separate this colouring matter, and to the filtered hquid is added an equal amount of alcohol at 95° C. By this means there is precipitated a blackish, gummy matter, insoluble in alcohol. The remaining hquid is decanted and once more evaporated until it is reduced to a smaller volume than before. It is again treated with twice its volume of absolute alcohol, when it precipitates, in addition to salts and gummy matter, a white flocculent substance, which is crude thalassin. This can be purified by redissolving it in alcohol at a temperature of 98° C. On cooling it separates from the fluid in the form of crystals, which are placed on a filter and can then be redissolved in a small quantity of water. Absolute alcohol, added to this solution, precipitates the thalassin in the shape of very pure crystals, which contain 10 per cent, of azote, and melt at 200° C. This substance, in aqueous solutions, rapidly deteriorates owing to ammoniacal fermentation. When injected intravenously into dogs it produces pruritus, sneezing, and erythema, with intense congestion of the mucous membranes ; 1 decigramme per kilo- gramme is a dose sufficient to produce these symptoms. It is not very toxic, since 1 centigramme is not lethal. One kilogramme of anemones is capable of furnishing about 3 grammes of pure crystallised poison. In addition to thalassin, Eichet succeeded in isolating from the tentacles of the same sea-anemones another poison insoluble in VENOMS IN THE ANIMAL SERIES 271 alcohol at 50° C, and richer in azote (14 per cent.), to which he has given the name congestin. This is not destroyed by heating to 107^ C. It is prepared by precipitating, by four times its volume of alcohol, a solution of anemone-tentacles in 5 per cent, fluoride of sodium. The solid matter, after being precipi- tated and dried, is redissolved in six times its volume of water, and then filtered. On adding to the filtered and fluorescent liquid its volume of alcohol at 90° C, the congestiji is precipi- tated. It is purified by redissolving it in water, and fi-eeing it by dialysis from the fluoride of sodium that it has retained. In this way there is obtained, after evaporation, a product sufficiently toxic to kill dogs in twenty-four hours in a dose of 2 milligrammes per kilogramme. Congestin exerts a sensitising or anaphylactic effect upon animals as regards thalassin, and is lethal in a dose of about 5 milligi-ammes per kilogramme of animal, and sometimes even in a dose of 7 decimilligrammes. It is therefore a very active poison. Dogs, on the other hand, into which is injected first thalassin, and then, some time afterwards, congestin, are perfectly resistant to inoculation by the latter. Thalassiii is therefore antitoxic or antagonistic to congestin. The latter, on the contrary, if injected first of all in non-lethal doses, renders animals so sensitive to inoculation with thalassi7i, that from 4 to 5 milligraiiimes are sufficient to cause death. The tentacles of these anemones therefore contain two toxic substances antagonistic to each other, which can easily be separated, since one {thalassin) is soluble in concentrated alcohol, while the other is completely insoluble in this reagent. These poisons are not only extremely interesting from a physio- logical point of view, but also possess a practical interest, since it is at the present time almost a matter of certainty that they are the cause of a malady which specially affects sponge-divers in the Mediterranean. 272 VENOMS A good description of the disease has been given by Dr. Skevos Zervos, of Athens.' It is observed exclusively in men who dive quite naked, without a diving-dress. Now, beside the bases of the sponges and sometimes on their surface there Hve numbers of anemones which secrete a viscid substance, which is extremely virulent, especially in the month of August. The first symptoms that supervene after contact with these Coelenterates are an intense itching and burning sensation ; a papule of a horny consistency appears at the outset at the spot at which contact took place ; this is soon surrounded by a red zone, which becomes bluish and then black, and spreads to a greater or lesser extent, according to the region attacked and the virulence of the venom. After a few days the skin sloughs and leaves a deep ulcer, which suppurates in spite of antiseptic treatment. The onset of the disease is marked by a febrile attack with shivering, which is soon accompanied by cephalalgia, thirst, and pains in the back and limbs. Zervos reproduced these disorders experimentally by rubbing an anemone, held with forceps, on the shaven abdomen of a dog. In a few minutes the region affected became quite red and prurigi- nous ; twenty-five minutes later phlyctense full of serum appeared ; three days afterwards five abscesses of different sizes developed, while at the place where it had been touched by the venom the skin assumed a deep blue colour ; on the fifth day an area 2 cm. in diameter was completely gangrenous. When ingested, anemones possess toxic properties which are well known to the sponge-fishers, for they frequently make use of them for the purpose of poisoning domestic animals. With this object they cut them up into small fragments, and mix them with bread or meat, which is given to the animals to eat ; the latter die in convulsions in a few minutes. In order to preserve the divers from the harmful effects produced Semadne medicale, June 24, 1903. VENOMS IN THE ANIMAL SERIES 273 by contact with the anemones, they should be advised to cover their bodies with a layer of grease, a simple artifice which con- stitutes an efficient protection. B. — ECHINODERMS. The Echinoidea (Sea-urchins) are provided with soft prehensile organs, the pedicellaricB, of which four kinds are distinguished : gemmiform, tridactyle, trifoliate, and ophiocephalous. These pedicellarise contain a special venom, which causes the paralysis and death oE animals into which it is injected. Uexkull, who was the first to mention it, considered that the gemmiform pedicellarise alone are toxic. From this point of view various species of sea-urchins, Strongy- loceyitrotus lividus, Arhacia cequituhercidata, Sphcsrechinus granit- laris and Spatangus purpureiis, have recently been studied by V. Henri. and Mdlle, Kayalof.^ The pedicellariae were removed and pounded up in sea-water, and the pulp was injected into crabs, holothurians, star-fish, cuttle- fish, frogs, lizards, and rabbits ; in the case of cuttle-fish and rabbits the injection was made intravenously ; in that of the other animals into the body-cavity. For crabs the lethal dose was from 20 to 30 gemmiform pedi- cellarise of Strongylocentrotus lividus. The holothurians, star-fish, and frogs proved immune. In the case of rabbits weighing 1^ kilogrammes, 40 pedicellarise of Sphcerechinus granularis, pounded up in 1 c.c. of water, produce death by asphyxia and general paralysis in froin two to three minutes. The heart continues to beat after respiration has ceased. For lizards and fishes the toxic dose is the same as for the crab. The cuttle-fish is paralysed and killed in two hours by 50 pedicellarise. ' Comptea rendus cle la Societe de Biologie, May 19, 1906. 18 274 VENOMS This venom resists ebullition for fifteen minutes. V. Henri and Mdlle. Kayalof made experiments in immunisa- tion. Babbits that receive every third day increasing doses of gemmiform pedicellarife of Sphcerechinus granularis tolerate well, after four injections, the toxin of 40 pedicellariffi, a lethal dose The serum of these rabbits is not protective for either rabbit crab, or fishes. Frog serum (1 c.c.) injected into the body cavity of a crab, protects this animal against the pulp of pedicellariae injected immediately afterwards. The pedicellariae easily become detached from sea-urchins. They remain fixed to objects which come into contact with them, and the urchin abandons them like poisoned arrows. On touching a point on the surface of the body of an urchin, the spines are seen to incline towards the spot touched, and the pedicellariae stretch themselves out and lean with their valves open towards the seat of the stimulus. In SpJmrechinus granularis the heads of the gemmiform pedicellariae are covered with sticky mucus forming a tiny drop, visible under the lens. A specimen of this species possesses more than 450 pedicellariae. C. — Arthropods. (a) j^raneida (Spiders). Almost all Arachnids possess poison-glands, which are con- nected, in some cases with the buccal apparatus, in others with a special inoculatory organ situated at the posterior extremity of the body. The spiders and scorpions belong to this group, and their venom is particularly active. On each side of the mouth of spiders is found an appendage ending in a fang (chelicera), at the extremity of which opens the excretory duct of a more or less developed poison-gland. The venom produced by these glands is instantly fatal to all small VENOMS IN THE ANIMAL SEBIES 275 animals upon which spiders feed. In man and large mammals their bite produces sensations of pain accompanied by swelling and muscular contractions as though caused by localised tetanus. The venom of certain species of spiders sometimes causes very serious and even fatal results. Latrodectus vialmignattus (the malmignatte of the South of France and Italy), and especially Latrodectus mactans, of Chile (fig. 96), are greatly dreaded.^ The area of distribution of the latter includes the whole of Tropical and Sub-tropical America. It is said that it frequently causes the death of milch cows, and that in man its bite produces tetanic effects, which last for several days, but are in most cases amenable to treatment. Another dangerous spider is the Katipo (Latrodectus scelio), of New Zealand. This creature is confined to the sea-shore, and the natives are often bitten when collecting shell-fish or sea-weed. The Maoris are so much afraid of the bite of the Katipo that, when one of them has been bitten in his hut, and the animal cannot be found, they do not hesitate to burn the dwelling to the ground. More- over, they are convinced that the death of the spider is absolutely necessary for the recovery of the patient.^ Pig. 96. — Lactrodectus mactans (formidabilis olim). 1, Female, twice natural size ; la, its eyes, greatly enlarged. ' " El Latrodectus formidabilis de Chile," by Frederico Puga-Borne, Santiago, 1892 ; and " Biologia Centrali- Americana," Arachnida, vol. ii., pi. 35. ^Blackwell, "Experiments and Observations on the Poison of Araneida," Transactions of the Linnean Society of London, 1855, p. 31. See also "Insect Life" (U.S. Department of Agriculture, 1889), vol. i., partis 7, 8, 9 and 10, and vol. ii., part 5. 276 VENOMS Kobert^ has made an experimental study of the venom of species of Latrodectus and Epeira. That of Latrodectus erebus (the Karakurte of South Eussia) is particularly toxic. If a dry extract of these spiders be prepared and injected into the veins of dogs or cats, it is found that a few milligrammes per kilogramme are sufficient to cause death, with phenomena of dyspnoea, convulsions, and progressive paralysis of respiration and the heart. Eabbits, rats, birds, frogs, and leeches are also sensitive to this poison, though the hedgehog is almost refractory, The youDg spiders, and even the eggs, are more toxic than the adults. Spider-venom is destroyed by heating for forty minutes at + 70° C, and is precipitated by alcohol. When absorbed by ingestion it has no effect : it is heemolytic and coagulates blood. The study of arachnolysin by Ehrlich's methods has been undertaken afresh by Hans Sachs, ^ who has shown that rat's and rabbit's blood are most rapidly dissolved. Twenty-eight milli- grammes of extract of Epeira are capable of completely dissolving 0'05 c.c. of blood. By immunising guinea-pigs and rabbits, Sachs succeeded in obtaining a strongly antitoxic serum, which entirely prevents the haemolysis of the sensitive red corpuscles. (b) Scorpionidea (Scorpions). The poison-apparatus of the scorpion is constituted by the last abdominal segment (telson), which is swollen and globular, and terminated by a hard, curved spine, with a very sharp point, near which can be distinguished, under the lens, two small oval orifices by which the poison is enabled to escape (fig. 97). The poison-glands are two in number, symmetrically placed in ' " Beitriige zui- Kenntniss der Giftspinnen." Stuttgai-t, 1901. 2 " Zur Kenntniss des Kreuzspinnengiftes," Hofm. Beitrdge, ii., p. 125, 1902. VENOMS IN THE ANIMAL SEBIES 277 cavities, each of which is completely filled by the gland. They are separated from each other by a muscular septum formed of striated fibres inserted in the chitinous skeleton ; by the contraction of this septum the animal is enabled to eject its venom. The scorpion never stings hachioards, but always in front of itself. It delivers stabs with its sting in two distinct ways. For Fig. 97.— Scorpio occitdniis. (After Joyeux-Laffuie.) 1, Scorpion seizing a spider, and piercing it with its sting (natural size) ; 2, extremity of the abdomen (telson) enlarged, showing the poison-apparatus ; 3, poison- apparatus detached from the abdomen, showing an isolated poison -gland. the purpose of defending itself from attack it elevates its abdomen into a bow, and then regains its former position by suddenly unbend- ing it. To strike an animal, such as a spider, which serves it for food, the scorpion seizes it with its pincers and holds it as in a vice. Then it raises its abdomen, brings the end of it close to its captive, 278 VENOMS and, with a lever-like movement, drives the sting into its body. The victim immediately becomes paralysed and motionless.^ The poison-glands of a Scorpio occitanus from the South of France contain about 1 to 10 centigrammes of a toxic liquid, capable of furnishing 10 to 16 per cent, of dry extract. This hquid is decidedly acid ; it reddens litmus paper and is miscible with water. Its physiological effects are especially intense in the case of the arthropods upon v/hich the scorpion habitually feeds, and in that of vertebrates in general. Batrachians, fishes, birds, and mammals are extremely susceptible to this poison. Half a milligramme of dry extract injected subcutaneously is sufficient to kill a guinea- pig, and 1 milligramme is lethal to the rabbit. ^n poisoned animals there is first observed a period of violent excitement, accompanied by very acute pains; these are followed by muscular contractions, and finally by paralysis of the respiratory muscles^ as in the case of intoxication by cobra-venom. The effects of scorpion-poison, which clearly indicate the presence of a neurotoxin, have been very well described by Valentin,- Paul Bert^ and Joyeux-Laffuie. Kyes^ has prepared a lecithide from scorpion-venom, which heemolyses red corpuscles as do the lecithides of cobra-venom, and I myself ^ have estabhshed the fact that the antivenomous serum of a horse vaccinated against cobra- venom effectively protects mice and guinea-pigs against intoxication by the venom of Scorpio occitanus; this has been verified by Metchnikoff. There is, therefore, a close affinity— Jbeiaggen this venom and that of Colubrine snakes. ' Joyeux-Laffuie, " Appareil venimeux et venin de scorpion " (Thesis for the degree of Doctor of Science), Paris, 1883 ; and Comptes rendus de V Academic des Sciences, November 6, 1882. ^ " Ueber die Giftwirkung des Nordafrikanischen Skorpiones," Zeitschrift fiir Biologie, Bd. xii., p. 170, 1876. ^ Comptes rendus de la Societe de Biologie, 1885, p. 574. Berliner Minische WocJienschrift, 1903, Nos. 42, 43. * Annates de VInstitut Pasteur, 1895, p. 232. VENOMS IN THE ANIMAL SERIES 279 On the other hand, it has been shown by the investigations of C. Nicolle and G. Gatouillard that tj^ same antivenomous serum has no e£fectu£on the much weaker venom of the scorpion of Tunis {HeterometriLS maurits), which, m the case of man and mammals in general, scarcely does more than produce a transient oedema at the point of inoculation. The venom of Heterovietrus maurus is, however, toxic enough to the sparrow. When one of these little birds is inoculated in the pectoral muscles with the contents of the poison-glands of a single scorpion belonging to this species, the following symptoms are observed : ^ntnediate rigidity, doubtless connected with the pain, then, after a few seconds, depression and relaxation of the muscles. The bird remains upright, but its body sinks down more and more until it comes into contact with the ground; if on a perch, it soon becomes unsteady and drops off. There is dyspnoea, which any effort increases, and death supervenes suddenly ; all at once the sparrow falls on its side, stiffens, sometimes has a few convulsions, and then finally becomes still. ~| The time occupied by these phenomena is always short, although it varies from two minutes to half an hour. ]^corpion- venom is a strong irritant to the mucous membrane^ AVhen dropped into the eye of a rabbit it produces acute ophthalmia. ^t has often been asserted that scorpions kill themselves with their own venom if enclosed in a circle of fir^ This is an absolute jnytb, for it is easy to prove by experiment, as was done_bxJ3ourne atMadras,^ that th^se animals ^jaM^fcbeJntoxicajifi^^ poisonous secretion^ nor by that of fpther individuals of the same speciesj Moreover, it has been established by Metchnikoff,^ in very definite fashion, that |tbe blood of the scorpion is antitoxj^ If 0"1 c.c. of this blood be added to a dose of venom lethal to mice in half an hour, a mouse injected with this mixture resists inde- finitely. This antitoxic power is exhibited both by Scorpio afer and the Algerian Androctonus. ' Proceedings of the Royal Society, vol. xlii., 1887, p. 17. ^ " L'immunit6 dans lea maladies iiifectieuses," Paris, 1901. 280 VENOMS Fig. 98. (c) Myriopods. It has been shown by PhisaHx and Bertrand that certain species of Myriopods, including those of the genus Julus (Order Chtlognatha, e.g., Julus terrestns), secrete throughout the entire extent of their body a volatile venom, which these authors com- pared to quinone. The species of the genus Scolopendra (Order Chilopoda ; Scolo- pendra cingulata, found in the South of France, Spain and Italy ; S. gigantea and other forms, common in Africa, India, Indo- China and Equa- torial America), have the second pair of post max- illary appendages transformed into formidable poison- claws, with which they can inflict bites which are very painful to human beings. The tropical species may attain a length of 10 or even 15 cm. Their bodies are composed of 21 segments, each provided with a pan: of jointed legs. They hve in shady places, such as woods, bidden under stones, dead leaves, or the bark of old trees. They feed upon small insects, spiders, and larvae, which they kill with their venom. The latter is secreted by a racemose gland situated at the base of the poison-claws ; it escapes by a duct which opens at the apex. This venom, the physiological study of which was commenced by Dubosq, is an acid, opalescent liquid, hardly miscible with water. More complete experiments on this subject have been made by A. Briot,^ who prepared a solution by sectioning the labium and poison-claws, and crushing the whole in physiological salt solution. When injected intravenously into rabbits, it produces immediate -Scolopendra ynorsitans (S. Europe). (After Glaus.) 1 Comptes rendus de la Societe de Biologie, November 15, 1904. VENOMS IN THE ANIMAL SEIilES 281 paralysis, with coagulation of the blood ; subcutaneonsly it leads to the formation of enormous abscesses, with necrosis of the tissues. Small animals, such as spiders, species of Saitigera, beetles, &c,, are very sen- sitive to it. The bite of Scolopendridce is very painful to human beings. In the Tropics such bites often cause some- what serious results : insomnia, ac- celerated and intermittent pulse, and local oedema, which usually disappears after twenty - four hours. Well- authenticated fatal accidents have never been recorded (Bachelier,^ Saulie^). (d) Insects. » M ,, bite dangerous, 100. Acantliopterygii, 290, 301, 304. Acanthurus, 301. ,, hcridus, 301. Adder, 25, 26. See also Vipera berus. Africa, poisonous snakes in, 57-81. II )) i> geographical distribution of genera (tables), 143, 144. ,, (Central), witch doctors of, snake-bite remedies, 237. ,, (East), Vatuas' method of inoculation, 239. Agglutinins of venoms, 202. Aipysurus, 140. ,, annulatus, 140. ,, australis, 140. ,, IcBvis, 140. ,, eydouxii, 140. Albuminoid of snake-venom produces haemorrhages, 162. Albumins of venom devoid of toxic power, 164. Albumose of snake-venom attacks nerve-cell of respiratory centres, 162. Albumoses of venoms of Colubridcs, 162. I) ,, ,, method of separation, 162. ,, See also Proto-albumoses, Hetero-albumoses. Alcatifa, extraction of venom from, for inoculation, 239. Alcock, researches of, on glands of snakes, 147. Alexins, 198, 209. ,, characteristics of, 207. ,, fixation of, 210, 211. ,, of normal serum, fixation by cobra-venom, 211, ,, neutralisation of, 212. Alkaloids in venom, 160. Alps, and mountains of Central Europe, Salamandra aira found in, 313. Amboceptors, 198, 210. ,, fixation of, 208, 220. America, snakes in, geographical distribution of genera of (table), 146. ,, venomous snakes in, 1 0-131 INDEX 373 America, (Central), Batrachus tau found on shores of, 302. ,, (North), musical toad found in, 318. (South), witch doctors of, snake-bite remedies, 237. (Tropical and Sub-tropical), Latrodectus mactans found in, 275. Ammonia, injection of, only temporary antidote against snake-venom, 261. ■ Ancistrodon, 49, 109, 110. . venom of, precipitation of anticoagulant substance in, 195. ,, acutus, 49. bilineatus, 111. blomhoffii, 50. ,, contortrix, 111. Imnalayanus, 50. ,, hyp7iale, 51. ,, intermedins, 50. J, piscivorus, 110. rhodostoma, 51, Anderson, relation of escape from Naja haje, 60. Anemone scuUata, 269. Aniline colours, a.ction of, diminishes toxicity of venoms, 167. Animals, venomous, definition of, 1. Arachnolysin, poison from Latrodectus prepared by, 276. Araneida (spiders), 274. Armstrong, H., chemical analysis of cobra-venom, 159. Arrows, poisoned by Hottentots with venom of Bitis arietans, 72. Arthropods, poisonous species of, 274. Asia, poisonous snakes inhabiting, 30, 57. „ geographical distribution of genera (tables), 142, 143. Asp, 27, 28. See also Vipera aspis Aspidelaps, 64. ,, luhricus, 64. scutatus, 64. Atheris, 78. ,, ceratophorus, 78. ,, chlorechis, 78. ,, sqtoamiger, 78. Atlantic (Tropical), Acanthurus found in, 301. Mtrisna monng^a found in, 309. Airactaspis, 78. ,, aterrima, 80. ,, bibronii, 80. ,, congica, 79. corpulenta, 80. ,, dahomeyensis, 80. ,, hildebrandtii, 79. ,, irregularis, 79. ,, leucoynelas, 81. ,, microlepidota, 81. ,, micropholis, 81. ,, rostrata, 80. 374 VENOMS Australia, health authorities' notices against venomous reptiles, 100. ,, mortality from snake-bite in, 100, 261. ,, poisonous snakes of, 81-100. „ snakes of, almost all confined to sub-family Elapina, 5. Bacteriolytic action of venoms, 206. " " ). how diSering from that of rat-serum, 208 Bailey, action of venom on brain, 185. Batrachians, 312. BatrachiidcB, 302. Batrachus gntnniens, 302. tau, 302. Bavay on the spitting snake, 63. Bee-sting, remedies for, 286. Bees, venom of, 282. Bertrand, researches of, 147. Bertrand and Phisalix, experiments on immunity of hedgehog to venom, 226. .. ,, preparation of toad-venom, 319. Bettencourt, E., venom antitoxin treatment of yellow fever, 184. Bibron and Dum^ril on coloration of snakes, 16. >> Naja worship in Egypt, 61. Bile, destructive effect on cobra- venom, 215. Birds, symptoms after inoculation with lethal doses of venom, 172 Bitis, 69. ,, arietans (puff adder), 69. '> >> ,, bite from, 350. )> >> venom used for poisoning arrows by Hottentots, 72. ,, atropos, 72. ,, caudalis, 73. cornuta, 73. ,, gabonica, 73. ,, does not attack man, 74. ,, inornata, 72. ,, peringueyi, 72. Black snake, 88. See also Pseudechis porphyriacus. Blin, bite from Cerastes, 349. Blindness following bite of viper, 178. Blood, anticoagulant action of venom on, mechanism of, 195. ,, coagulability, action of venom of Lachesis lanceolatus on, 191. destroyed by venoms of Colubridce, 179, 188, 189, 191, 192, 193. >' " >> certain species of CrotoKnffi, 191, 192, 193. „ „ uncertain action of venom of Vipera berus on, in certain animals 189, 190. ,, coagulation of, connected with action of venoms of Viperidce on nervous system 185, 186. „ „ produced by venoms of ViperidcB, 179, 188, 189. ,, not coagulated after death caused by venoms of Colubridce, 171, 188, 189. ,, of hedgehog toxic before heating, antitoxic afterwards, 226. ,, of scorpion antitoxic, 279. INDEX 375 Blood, toxicity of, in reptiles, 217. confers partial immunity to venom, 218, ^19. destroyed by heating, 218. in venomous snakes, 217. Blood-corpuscles, red, agglutination by venoms, 202. dissolution only effected by combination of venom with blood- serum or lecithin, 197. dissolved by snake-serums, 219, 220. effects of venom upon, 196. resistance to large doses of venom, 199, 200, 201. " " „ „ explanation, 200, 201. " "^^ washing of, important before presentation to action of venom, 196 197. unaltered under action of simultaneous doses of venom and serum, 220. white, effects of venom on, 20.3. Bombay' laboratory for production of antivenomous serum at, 248, 252. Bonaparte, Lucien, chemistry of venom of vipers, 160. Bothrops, bites from, 353, 354. Bottard on venomous fishes, 288. Boulengerina, 58. stormsi, 58. Brachyaspis, 95. ,, curta, 95. Brain, comparative action of venoms of ColuhridcB and Viperida on, 185, 186. ,, substance of, fixation of venom on, 186. Brazil, Thalassophryne maculosa found on shores of, 303. Brehm, on Crotalus confluentus, 125. ,, the daboia (Vipej-a russellii), 46. ,, Echis carinatus (efa, viper of the pyramids), 76, 77. ,, reverence paid by Hindus to Naja, 38. Broad-headed snake, 94. See also Hoplocephalus variegatus. Briot, A., experiments with weever-venom, 298, 299. ,, poison of Scolopendra prepared by, 280. Bromized water, saturated, modifies or destroys venoms, 164. Brown snake, 87. See also Diemenia textilis. Brunton, Sir Lauder, on harmless ingestion of venom exceeding lethal dose, 214. Bufo calamita (natter-jack), 318. ,, musicus (musical toad), 318. ,, widis (green toad), 318. ,, vulgaris (common toad), 318. Bufotalin, 319, 320. „ first active principle of toad-venom, and cardiac poison, 319, 320. Bufotenin, 320. second active principle of toad-venom, and neurotoxic poison, 320. Bungarus, 30. , , venom of, active hsemolysing power possessed by, 199. ,, cceruleua (common krait), bite, cure of, 337. venom of, dose lethal for different animals, 174. candidiiSj 32. 376 VENOMS Bungarus candidus, resemblance to Lycodon aulicus, 33. fasciatus, 81, 32. Buprestidcc, food for larvte of Cerceris bupresticida, 285. Bushmaster, or surucucu, 112. See also Lachcsis mutus. Calamaridje. species of Callophis feed only upon, 42. Callionyimis, 301. ' ' >, helennus, 301. M lacertus, 301. lyra, 300-301. ,, vulsus, 301. Callophis, 40. ,, feeds only on snakes belonging to Calamarida, 42. ,, bibronii, 41. „ gracilis, 41. „ maclellandi, 41. maculiceps, 41. trimaculatus, 41. Calmette's serum, cobra-bites treated witb, 363-5. 5ee also Serum, antivenomous. Calvados, Callionymus lyra common on coast of, 301. Cantharis (blister-beetles), 281. Cantor, on venom of Naja hungarus, 39. ,, vindictiveness of Naja bungarus, 39. Captivity, poisonous snakes kept in, 61, 62, 125, 156, 223. Caravyalla. See Ancistrodon hypnale. Cardiac poison of toad-venom (bufotalin), 319, 320. Caribbean Sea, Scorpcena grandicornis found in, 293. Carpi and Morgenroth, lecithide of bee-venom prepared by, 285. Carri^ire, experiments on ingestion of venom, 214. Cascavella (Crotalus terrificus), 124. Cato, army of, patronage of snake-charmers by, 228. Cai(,sus, 67. ,, defilipii, 67. „ lichtensteinii, 68. ,, resimus, 67. ,, rliombeatus, 67. ' Cells, dissolution of. See Cytolytic action. Cerastes, 4J1, 75. ,, bites from, 348-350. )> n cured, 358. secretion of, 150. ,, venom of, fatal to barefooted pedestrians, 76. „ cm-mUics, 47, 75. ,, viper a, 75. Cerceris bupresticida, 285. Ceylon, snake-charmers of, 229. Chameleons succumb rapidly to snake-poisoning, 172. Chelicera (fang of spider), 274. Chemical reactions exhibited by venoms, 162. INDEX 377 Chemical substances modifying or destroying venoms, 164. Chemistry of snake-venoms, 159. Cherry and Martin on antagonism between toxins and antitoxins, 253. Ghilornycterus, 307. ,, orhimlaris, 307. ,, tigrinus, 307. China and Japan, Lophius setigerus found in seas of, 304. Chloride of gold, antidote to venom before absorption, 261, 263. ,, solution, modifies or destroys venom, 164. ,, lime solution, modifies or destroys venom, 164. Cholesterin, antidote to lecithin, 198. Chromic acid, antidote to venom before absorption, 260. ,, ,, solution, modifies or destroys venoms, 164. Clamouse, on bites from European vipers, 343. Clot Bey on Egyptian snake-charmers, 228-229. Clothing protective against dangerous effects of snake-bite, 170. Cobra, bite of, clinical symptoms, 169. „ ,, ' exhibit rapid generalintoxication, 169. „ ,, treated with Calmette's serum, 363. ,, extraction of venom from, method, 153. ,, Egyptian (Naja haje or liaie), 59. „ method of carrying after capture, 21. ,, snake-charmers' skill with, 229. ,, venom of, 149. ,, ,, alkaloids in, 160. ,, ,, chemical analysis, 159. comparison of toxicity by means of intra-cerebral injections, 186. ,, destructive action of bile on, 215. ,, ,, dissolution of trypanosomes by, 207. ,, ,, dose lethal for different animals in twenty-four hours, 174. ,, ,, fixation on nervous elements, 186. „ ,, local effects on serous membranes slight, 179. ,, ,, potency of antineurotoxic antivenomous serum against, 250, 251, 252. ,, ,, vaccination against, 242, 244, 245. Cobra-di-Capello, 33. See also Naja tripudians. ,, ,, spectacled, used by Hindu snake-charmer, 229. Ccelenterates, poisonous species of, 269. Ccelopeltis, 22. ,, moilensis, 23. ,, monspessulana,23. Cold, intense, toxicity of venom not diminished by, 166. Colombia, herons of, probably immune to snake-venom, 227. ,, ,, hunt young snakes for food, 226. Coloration of snakes, 15, 16. ,, ,, subject to biological laws of mimicry, 15, 16. Colubrida:, 3, 30, 57, 82, 100, 101-109. See also Acanthophis, Aspidelaps, Boulengerina, Brachyaspis, Dendraspis, Denisonia, Dieinenia, Elapechis, Elapognathus, Furina, Qlyphodon, Homorelaps, Hoplocephalus, Micropechis, Notechis, Ogmodoii, Opisthoglypha, ProterogUjpha, Pseudechis, Pseudelaps, Bhinhoplo- cephalus, Bhynchelaps, Sepedon, Tropidechis, Walter innesia. 378 VENOMS Colubridce (sub-family Elapina!). See also Bungarus, Naja, Eemibungarus, Callophis, Doliophis. resemblance to harmless, snakes, 3. species of, bite rapidly produces general intoxication, 168. venoms of, absorption by digestive tract often without ill-efEect, 180, 181. >• i> >' .. ,, ,, cause, 181. ,, action on nervous centres profound, 185. ,, affinity of scorpion poison to, 278. ,, albumoses of, 162. destroy coagulability of blood, 179, 188, 189. ,, dialyse slowly, 161. ,, lethal effects on mammals, 170. minimum doses lethal for guinea-pig in twenty-four hours, 17.3. • ,, precipitation of anticoagulant substance in, 195. ,, recovery rapid after non-lethal doses, 177. ,, resistant to heat, 161. ,, richness in neurotoxin, 249. Common rattle-snake, 125. See also Crotalus durissus. Congestin, poison from Anemoiie scuUata, 271. Conjunctivitis caused by discharge into eyes of venom of spitting snake, 63, 64. Copperhead, 90. See also Denisonia superba. Coral-snake, 104. ,, immunity from bite of, 288. ,, venomous nature of, 108. See also Elaps corallinus. Coral or harlequin snake, 106. See Elaps fulvius. Cordier, D. , cobra-bites treated with Calmette's serimi, 363. Cotes, E. C, on extraction of venom by charmers, 234. Cotkis, 289, 290, 292. poison-apparatus of, 293. CrabronidcB, 285. ,, stings of females of, toxic to other insects, nearly harmless to man, 285. CrotalincB (Viperida), 101, 109. ,, characteristics of, 6. ,, venoms of certain species of, non-coagulant, 191, 192, 193. , , See Ancistrodon ; Lachesis. Crotalus (rattle-snake), 110, 122. comparative toxicity of organs, 220. eggs of, rich in poison, 220. poison glands of, 148. venom of, alkaloids in, 160. ,, comparison of toxicity by means of intra-cerebral injections, 186. ,, ingestion causing death, 180. ,, weak haemolysing power possessed by, 199. adamanteus, venom of, dose lethal for rabbit, 175. cerastes (horned rattle-snake),' 129. confluentus (Pacific or mottled rattle-snake), 124. ,, ,, ,, ,, habits, 125. ,, devoured by pigs, 125. INDEX 379 Crotahis confluentus, secretion of, 150. ,, dzwissMS (common rattle-snake), 125. , , horridus, 127. „ bites from, 355. ,, lepidus, 129. ,, viitchelli, 127. polystictus, 129. scxMatus (Texas rattle-snake) , 124 . terrificus (dog-faced rattle-snake or cascavella), 124. ,, tigris, 127. tHseriakis, 129. Gryptobranchus japonicus (great lapajiese salamander), 313-315, 317. • ,, venom of, 317. action similar to that of viperine venoms, 317. Gurados de Culebras, immunity produced by inoculation by, 235-237. Cytolytic action of venoms, 206. Daboia. See Vipera russellii. Deafness following bite of viper, 178. Death adder, 96. See also Acanthophis antarcticus. Delezenne, establishment of existence of kinase in venoms, 204. „ on the kinasic properties of venoms, 204, 213. Dendraspis, 65. ,, angtosticeps, 66. ,, antinorii, 66. ,, jamesmiii, 66. viridis, 66. De7iisonia, 88. ,, carpentarice, 92. coronata, 89. ,, cmvnoides, 89. ,, dcemelii, 90. ,, flagellum, 91. ,, frenata, 90. ;, frontalis, 91. gouldii, 91. ,, maculata, 91. ,, melanura, 92. ,, muelleri, 90. ,, nigrescens, 92. ,, nigrostriata, 92. ,, pallidiceps, 92. par, 92. ,, punctata, 91. ramsayi, 90. ,, signata, 90. superba (the copperhead), 89. ,, suta, 90. woodfordii, 93. 380 VENOMS Dialysis, results of, in experiments with venoms of Coluhrida and Viperida, 161. Diastases, action upon venoms, 214. Diastasic actions of venoms, 212. Diemenia, 86. 7nodesta, 87. nuchalis, 87. olivacea, 87. psammophis, 87. textilis (brown snake), 87. i> ,, bite dangerous, 100. torqzcata, 87. Digestion of snakes aided by venoms, 213, 214. Digestive tract, absorption of venoms of CohibridcB often without ill-effect on, 180, 181. r>- j" „„.-" " " " " >• cause, 181. Diodon, 305. Dipsadomorphinai, sub-family of Opisthoglypha, 8. ,, geographical distribution, 4. Dipsas, teeth of, 8. Distira, fresh-water genus of Hydrophiince, 5, 136. „ cyanocincta, 137. ,, jerdonii, 137. ,, cn-nata, 136. ,, subcincta, 137. Dog, minimal dose of cobra- venom lethal for, 174. Dog-faced rattle-snake, 124. See also Crotalus terrifictts. Doliophis, 42. ,, hilineatus, 43. bivirgatus, 42. ,, iiitestinalis, 42. ,, philippinus, 43. Domestic animals, treatment of poisonous bites in, 265. Duck-billed platypus (Ornithorliynchus paradoxus or 0. anatinus), 328. Dumdril and Bibron, on coloration of snakes, 16. ). Naja worship in Egypt, 61. Dutch Indies, poisonous snakes inhabiting, 80-57. Dyer, venom antitoxin treatment of yellow fever, 184. DE Javel, antidote to venom before absorption, 263. ,, ,, in treatment of wasp- or bee-stings, 286. Echidnin, chemistry of, 160. Echinoidea (sea-urchins), 273. Echinoderms, poisonous species of, 273. Echis, 48, 76. ,, carinatus (efa, viper of the pyramids), 48, 76. ,, ,, bite from, 347. „ ,, dreaded by Egyptians, 77. ,, ,, venom rapid in action, 49. ,, color atus, 77. INDEX Efa (Echis carinatus), 48, 76. See also Echis carinatus. Eggs of bees, venom coataiued in, 284. fowls, artificial intoxication by venom, effect on embryo, 214. Crotahis rich in poison, 220. Egypt, laboratory researches in, 149, 150. ,, snake-charmers of, 228-229. Egyptians, dread of Echis carinata (Efa) shown by, 77. " ,, and pursuit of i^a/a /laje among, 60. Ehrlich, theory of lateral chains, 208, 220. ElachistodontincB, sub-family of O^nsthoglypha, 3. ,, geographical distribution, 4. Elapechis, 58. ,, houlengeri, 59. ,, decosteri, 59. ,, hessii, 59. ,, guentheri, 58. ,, niger, 58, 59. ,, sundevallii, 59. ElapincB, sub-family of ColitbridcB, 30. ,, geographical distribution, 5. Elapognathus, 97. ,, minor, 97. Elaps, 101, 108. ,, anco7-alis, 108. ,, annellattis, 103. ,, anomalus, 103. buckleyi, 103. ,, corallinus (coral snake), 104. See also Ooral-snake. ,, decoratus, 104. ,, dissoleucus, 106. ,, dumerilii, 104. ■ ,, elegans, 103. ,, euryxanthus (Sonoran coral-snake), 102. ,, filif minis, 107. ,, fraseri, 107. ,, frontalis, 106. ,, fulvius (harlequin or coral-snake), 106. ,, gravenhorstii, 102. ,, hemprichii, 104. ,, heterochilus, 102. ,, heterozonus, 103. ,, langsdorffii, 103. ,, lemniscatus, 107. ,, marcgravii, 106. ,, mentalis, 107. ,, mipartitus, 107. , , narduccii, 108. ,, psyches, 106. ,, spixii, 106. 382 VENOMS Elaps surinamensis, 102. ,, tschudii, 104. Electricity passed through solution of venom in form of, continuous electrolytic current destroys toxicity, 165. Sec also High frequency currents. Embryo, canomalies in development consequent on introduction of venom into eees of fowl, 214. Enhydrina, 139. „ venom of, fixation on nervous elements, 186. ,, bengalensis (syn. E. valakadien), 139. ,, valakadien (syn. E. bengalensis), 139. .. >> venom of, dose lethal for different animals, 174. Enhydris, 138. ,, curtus, 138. ,, venom of, dose lethal for rat, 174. Entomophaga, 286. Eosin, photodynamic action of, diminishes toxicity of venoms, 167. Epeira, 276. Erythrosin, photodynamic action of, diminishes toxicity of venoms, 167. Europe, poisonous snakes inhabiting, 22-29. ,1 geographical distribution of genera (tables), 142. ,, (Central). See Alps. ,, Triton cristatus and T. marmoratus found in, 313. Ewing, action of venom on brain, 185. Facial bones, special arrangements of, characteristic of poisonous snakes, 6. Pasting, prolonged, snake-venom shows greatest activity after, 176. Faust, S., salamandrine prepared by, 316. Payrer, Sir J., fatal results of experimental ingestion of venoms, 180. ,, ,, on the daboia {Vipera russellii), 47. ,, ,, h&hits ol the kr&it (Bungarus candidus), 33. ,, ,, harmless ingestion of venom exceeding lethal dose, 214. ,, ,, Naja bungarus, 39. Feeding, artificial, in laboratories for collection of venom, 157. ,, ,, of poisonous snakes, 17, 18. Fer-de-lance {Lachesis lanceolatus), 112, 113, 114. Fere, Ch., experiments on development of embryo after introduction of venom into fowl's egg, 214. Fishes succumb rapidly to snake-venom, 172. venomous, 288. ,, ,, poison-apparatus of, 289. Flexner and Noguchi, on action of snake-serum on red corpuscles, 219. ,, ,, cytolytic action of venoms, 206. ,, ,, investigations on toxicity of snakes' organs, 220. Food, abstinence from, by snakes, 149. Fowls killed by causing them to ingest venom, 180. Fox, W. A., bite from Sepedon liccmachates, 337. France, mortality from snake-bite in, 3. Fraser, on destructive action of bile on cobra-venom, 215. INDEX 383 Frog-serum, antidote to poison of pedioellariae, 274. Frogs succumb slowly to snake-poisoning, 172. Furina, 98. bimaculata, 99. ,, calonata, 99. ,, occipitalis, 99. Gaboon viper, 73. See also Bitis gabonica. Gangrene, produced by venom of ViperidcB, 177. Gautier, Armand, chemical constituents of venom, 160. Geographical distribution of poisonous snakes in Africa, 143, 144. „ America, 146. Asia, 142, 143. ,, Europe, 142. * ,, Oceania, 145. Geracki, collection of venom, 156. Gibbs, Wolcott, chemical constituents of venom, 160. Glands (acid and alkaline), poison-organs of the hymenoptera, 282. ,, secretion of venom from, 147. Glandular secretions of persons and animals bitten by venomous snakes, toxic, 181, Glycerine, means of preservation of concentrated solution of venom, 166. Glyphodon, 83. ,, tristis, 84. Gohiida, 300. Gouzien, Paul, collection of venom from poisonous snakes in French settlements m India, 359. „ on collection of venom, 156. Grage (Lachesis atrox), immunity frorh bite of, 238. Grass-snakes, parotid glands of, 147. „ withstand large doses of venom, 172. Gressin on poisoning from weever-stings, 299. de Gries on bites from Bothrops, 353, 354. Ground rattle-snake, 120. See also Sistrurus miliarius. Grunting batraohus. See Batrachics gnmniens. Guiana, witch-doctors of, snake-bite remedies, 237, 238. Guinea-pig, minimal doses of various venoms lethal for, 173, 174, 175. vaccination against cobra-venom, 242. HiEMOLYSiNS of venom, resistance to heat, 202. Haemolysis, failure of, under exposure of red corpuscles to large doses of venom, 199, 200, 201. ,, in venoms, comparative study of, 196. ,, power of, possessed by various venoms, 199. Hemorrhages produced by albuminoid of snake-venom, 162. ,, visceral, complicating recovery from bites of ViperidcB, 177, 178. Hsemorrhagin in venoms, 187. ,, local effects of, not prevented by antineurotoxic serum, 251. predominance in venom of ViperidcB, 249. 384 VENOMS Hajmorrhagin, present in some species of ViperidcB, 249. ,, sensitive to heat, 249. Harnadryas elaps, 37. See also Naja bungarus. Harlequin or coral snake, 106. See also Elaps fulvius. Heart, action of venom on, 184. Heat, comparative effect on venoms of Goluhridce, HydrophiidcB and Viperidce, 161. hsemorrhagin sensitive to, 249. ,, resistance of hssmolysins of venoms to, 202. ,, sole agent in attenuating venom submitted to alternating high frequency currents 165. Heating destroys toxicity of blood of reptiles, 218. Hedgehog, immunity of, to venom of Vipera berus, 226. M >• „ ,, proved experimentally, 226. ,, blood of, toxic before heating, antitoxic afterwards, 226. Heloderma horridum, 321. ,, ,, saliva sometimes toxic, sometimes harmless, 323. ,, ,, venom of, 321, 322. Hemibungarus, 39. ,, calligaster, 40. ,, collaris, 40. * ,', ' japonicus, 40. ,, nigrescens, 40. Henri, V., poison from pedicellariaj prepared by, 273. Herons of Colombia hunt young snakes for food, 227. ,, ,, probable immunity to snake-venom, 226, 227. Hetero-albumoses, active principle of snake-venom, 164. ,, separation from snake-venom, 162, 163. Heterometrus maii7-us, venom of, 279. ,, ,, ,, efiect upon sparrows, 279. High frequency currents, alternating, attenuate venom only by thermic action, 165. Hill, Patrick, on duck-billed platypus, 324. Hindus, worship bestowed on Naja by, 38. Holbrook on Crotalus confluentus, 125. Holocanthus, 305. ,, imperator, 305. HomalopsincB, sub-family of Opisthoglypha, 3. ,, geographical distribution, 4. ,, aquatic, 4. Homorelaps, 57. Hoplocephalus, 93. ,, bitorquatus, 94. ,, bungaroides (syn. H. variegatus, broad-headed snake), 94. ,, curtus (Notechis scutatus, tiger-snake), 95. ,, ,, ,, ,, ,, bite dangerous, 100. ,, ,, ,, ,, • ,, secretion of, 149. ,, stephensii, 94. Horned rattle-snake, 129. See also Crotalus cerastes. Horse, bleeding, aseptically, after vaccination to obtain antivenomous serum, 245, 246. ■ ,, immunisation to venom, difficulties attending, 244, 245. INDEX 385 Horse, minimal dose of venom lethal for, 176. ,, polyvalent serum prepared from, 251. red corpuscles of, reasons for choice of, for exposure to action of venom, 196, 197. ,, vaccination of, against cobra-venom, 244, 245. Horse-serum must be added to venom to dissolve washed red corpuscles, 197. Hottentots, venom of Bitis arietans employed for poisoning arrows by, 72. Hydrelaps, 134. HydrophiidcB (sea-snakes), 100. „ . bite from, cure, 338. rapidly produces general intoxication, 168. ,, venoms of, resistant to heat, 161. Hydrophiince (sea-snakes), 4, 131. habitat and geographical distribution, 4, 5. habits of, 131. Hydrophis (sea-snakes), 134. ,, venom from, 360. ccBrulescens , 135. cantoris, 135. elegans, 135. fasciatus, 136. gracilis, 135. leptodira, 136. nigrocinctus, 135. obscurus (syn. H. stricticoUis), 136. spiralis, 135. Hydrus, 182. Hymenoptera, 281. ,, poison-glands of, 281, 282. Hypochloride of calcium solution modifies or destroys venoms, 164. Hypochlorite of lime, antidote to venom before absorption, 261, 263. ,j ,, remedy for wasp- or bee-sting, 286. Hypochlorites, alkaline, antidotes to venom before absorption, 261. Hypoleucocytosis, accompanying snake-bite, in lethal cases, 211, 212. following fatal dose of venom, 216. Immunity to venom, active, incontestably possible, 240. doubtful, by Vatuas' method, 239. hereditary, pretended, 238. ,, ,, in India and Egypt, 240. natural, 222. partial, enjoyed by snakes due to diastasic substances in blood, 218, 219. in lethal doses not conferred by ingestion of venom, 215. India, French Settlements in, collection of venom and treatment of bites from poisonous snakes in, 359. ,, legend relating to Naja in, 37. ,, mortality frorn snake-bite in, 2, 38, 363. ,, ,, ,, ,, excessive, due to snake-worship, 2. ,, ,, ,, Naja bites, 38. 26 386 VEJN0M8 India, poisonous snakes inhabiting, 30-57. „ snake-charmers in, 229-234. ,, ,, remedies for bites, 237. ,, Te7. ,, scorpion -venom, 278. Lecithin, added to venom to dissolve washed red corpuscles, 197. ,, cholesterin antidote to, 198. ,, combination with snake-venom, 254. Leipothymia following inoculation of venom of Synanceia brachio, 292. Le Naour, on the spitting snake, 63. Leucocytes, protective role against snake-poisoning, 216. Leucolysin, mode of producing, 203. Lewin, experiments on immunity of hedgehog to venom, 226. Leydig, researches of, 147. Lhomme, bite from Lachesis ferox, 351. ,, collection of venom, 156. Light, destructive effect of, on venom in solution, 165, Liver, action of venom on, 182. Livingstone, mention of Naja haje by, 60. Lizards, 321-323. ,, only one species venomous, 322. ,, succumb rapidly to snake-poisoning, 172. Lophius, 804, ,, piscatorms, 301. ,, setigerus, 303-304. Lucan, passage from, quoted, on immunity of Psylli, 240. Lumiere, A., and Nicolas, J., on effect of intense cold on venom, 166. Lungs, action of venom on, 184. Lycodon aulicus, resemblance of Bungarus candidus to, 33. Maclaud, bite from Naja haje, 356. INDEX 389 Madsen, Th., aad Noguchi, H., on ratio between doso of veuom and time elapsing till death, 177. Mai on Hindu snake-charmers, 229. Malaysia, poisonous snakes of, 81. Mahnignatte, 275. Mammals, action of Colubrine venom on, symptoms and coarse, 171. ^jos^-woriem findings, 171. Viperine venoms on, symptoms and course, 171. post-mortem findings, 171. Man, minimal dose of venom lethal for, 176. not attacked by Bitis gabonica (Gaboon viper), 74. Mano de sapo root, eaten by Mexicans during immunisation treatment, 236. Maoris' fear of Katipo, 275. Marohand, on bites from European vipers, .339. Mariadassou, P., serum treatment, 368-371. Mariapregassam, collection of venom, 361. Marotte, on Naja haje bite, 356. Martin, C. J., chemical constituents of venom; 160. ,, ,, experiments on Pseudeclds, 162. with rats proving harmlessness of ingestion of venom of PsettfZ- echis, 181. ,, on venom of Ornithorhynchus, 324. and Cherry, on antagonism between toxins and antitoxins, 253. '', ',' and Smith, MacGarvie, on local and general effects of albumoses derived from snake-venom, 163. Martinique, mortality from bite of fer-de-lance in, 113. Massasanga, 120. See also Sistrwus catenatus. de Maupas on Pelias berus bite, 857. Mediterranean Sea, Murcena Helena found in, 809. ,, Scar pcB7ia pomis tonnd in, 294:. Medulla, substance of, fixation of venom on, 186. Meloe (oil-beetles), 281. Mexico, inoculation of natives in, successful, 235-237. Micropechis, 93. ,, elapoides, 98, ikaheka, 98. Milk from mother bitten by poisonous snake causing death of young, 181, 214. Mimicry, biological laws of, coloration of snakes subject to, 15, 16. Mitchell, S. "Weir, on chemical constituents of venom, 160. fatal results of experimental ingestion of venoms, 180. ,, harmless ingestion of venom exceeding lethal dose, 214. Moindrot, H., bites from European vipers, 345. Molluscs, poisonous species of, 286. Mongoose, battles with hamadryads and cobras, 223, 224. ,, ,, victory mainly due to natural agility, 225. ,, immunity to snake-venom, 223. ,, ,, ,, not absolute, 225. ,, ,, ,, proved by injections, 224, 225. Mnnotremata. See Ornithorhynchus paradoxus or 0. anatinus. 390 VENOMS Mons on bite from horned viper, 349. Morgenroth, on combiuation of venom with lecithin, 254. .. reconstitution of toxins, 257. ,, and Carpi, Iccithido of bee-venom prepared by, 285. Mortality from bite of Naja in India, 38. >> )> T'ipcj-a 6mts (common viper or adder), 27. >> 1. poisonous snake-bite ; localities : — Australia, 100, 251. France, 3. India, 2, 88, 363. Martinique, 113. Mottled Rattle-snake 124, 125. See also Crotaius confiuentus. Moudon, on bite from Cerastes, 348. Moult of snake's skin, 16, 20. ,, venom shows greatest activity after, 176. Mouse, experiments on, demonstrating neutralisation of venom by antitoxin, 254. Mucous membranes, acute inflammation produced by deposit of venoms on, 180. MurcBna, 309. ,, poison apparatus in buccal teeth, 288. of, 309, 310. ,, helena, 309. ,, moringa, 309. MurcBuidcB, 307, 309. Murex brandaris, 286. ,, truncuhis, 286. Murison, Lieutenant C. C, on bite from Echis carinata, 347. Muscles, striated, action of venoms on, 184. Muscular apparatus of head of poisonous snakes, 11, 12, 13. Myriopods, venomous species of, 280. Naja (cobra), 33, 59. habits of species of, 37. legend relating to marks on its neck, 37. mortality from bite of, in India, 38. poison-glands of, 148. venom of, active hsemolysing power possessed by, 199. worship bestowed on, by Hindus, 38. anchietce, 62. bungarus {Oiihiophagus or Hamadryas elaps, king cobra or hamadryad), .37, 38. ,, action of venom, 39. ,, feeds on other snakes, 38. ,, killed by mongoose, 223. ,, method of procuring food, 38, 39. ,, vindictiveness of, 39. fiava, 61. goldii, 62. haje or liaie (Egyptian cobra), 59. ,, bites from, 356. INDEX 391 Naja haje, danger extreme from its boldness in pursuit of victims, GO. dreaded and hunted down in Egypt, GO. ,[ employed by Egyptian snake-charmers, 61. ,, secretion of, 149. tables, 150. [] worshipped among ancient Egyptians, Gl. ,, melanolexica, 62. ,, nigricollis, 62. ,, samarensis, 36. tripudians (Cobra-di-capello), 33-36. collection of venom from, 156, 360. marks produced on skin by bite of, 10. muscular apparatus of head of, 11, IS. poison-gland of, 11, 13. var. ccBca, 35. ,, fasciata, 35. - ,, miolepsis, 36. ,, sputatrix, 35. typica, 34. Naseus, 301. Natter-jack, 318. Neurotoxic and heemolytic actions of venoms, parallehsm between, 255. Neurotoxin, 191, 195. essential active substance in venoms, 187, 250. highly resistant to heat, 249. of scorpion-poison, 278. of toad-venom (bufotenin), 320. potency of antineurotoxic serum against, 250, 251. predominance in venom of Colubridce, 249. present in venoms of some species of Viperidm, 249. Neuwied on Flaps, 108. New Caledonia, terrestrial poisonous snakes unknown in, 100. New Guinea, poisonous snakes of, 81-100. New Zealand, Katipo found in, 275. no poisonous snakes in, 100. Nicolas, J., and Lumiere, A., on effect of intense cold on venom, 166. Noc, on action of different venoms, 190, 191. _ bacteriolytic property of venom, with respect to difierent micro- organisms, 207, 208, 209. heemolytic powers of venoms, 196. study of venom of Ornithorhynchus, 324. Noguchi, H., on action of aniline colours on venom, 167. failure of hcemolysis under large doses of venom, 200, 201. and Plexner, cytolytic action of venoms, 206. investigations on toxicity of snakes' organs, 220. on action of snake-serums on red corpuscles, 219. [[ Madsen, Th., on ratio between dose of venom and time elapsing till death, 177. Normandy, coast of, Coitus abundant on, 292. 392 VENOMS Notechis, 95. scutahis (syn. Hoplocephalus curtus, tiger-snake), 96. " " " >> >. bite dangerous, 100. " " venom of, dose lethal for rabbit, 175. Oceania, geographical distribution of genera of poisonous snakes (tables) 145 Oglmdm 1° ^""'"^ ^''"''''^ °^ overpowering prey, 287. I, vitianus, 82. Oil beetles, 281. See also MeloS. Ophiogeni in Egypt, 228-229. " Ophiophagus, 37. See also Naja bungarus. Ophthalmia, purulent, produced by snake-venom experimentally, 180. " " venom of species of 5e»edo9i, 180. Opisthoglypha, group of CohtbridcB, 3. sub-families of, 3. See also Homalopsina:, Dipsadomorphma, Elachisto- dontince. " » slightly poisonous and not dangerous to man 4 Ui-mthorhyncMis paradoxus, or O. anatinus (duck-billed platypus), 323. " " " .> „ venom of, 324, 325. " " " >> >. action similar to venoms of Viperida, 324. " " " >> ,. toxicity very slight, 325. Pacific Ocean (Equatorial), Pterois found in, 296. ,, (Tropical), Scorpccna diabolus found in, 293. " " >) 'S'2/«aMcem irac/iio most commonly found in, 29]. _ „ rattle-snake, 124, 126. See also Crotalus confluentus. Pain, severe, after bite of species of ViperidcB, 169. ,, slight from bite of cobra, 169. VB.Ta&ma,, Thalassophryne reticulata found on shores of, 303. Pancreatic juice, addition to venom produces kinasic power, 213. Paris, brown Pelohates found near, 318. Parotid glands, venomous secretions, 147. Pasteur Institute (Lille), poisonous snakes in captivity at, 72. " >' II preparation of antivenomous serum at, 245-248. " >. 1. rattle-snakes in captivity at, 125. '» " >> work and experiments at, 189, 190, 191, 204, 214 223 224 244- 248, 267. ' ' Paterne, D., bites from European vipers, 341. Peal, H. W., on bite from Hydrophiidcc (sea-snakes), 338. Pedicellariee (organs of the EcUnoidea), poison prepared from, 273. Pediculati, 303. Pedlar on chemical constituents of venom, 160. Pelias berus (common \iper), bite from, 339. " " )i II ,, cure, 357. Pelohates fuscus (brown Pelobates), 318. Pelor, 293, 29G. PercidcE, 304. INDEX 393 Peritoneum, hemorrhagic injections of, produced by vehoms of Viperidce, 179, 180. Permanganate of potash, antidote to venom before absorption, 2G0. solution, modifies or destroys venoms, 164. Philadelphia, laboratory for production of antivenomous serum at, 248, 252. Philippine Islands, poisonous snakes inhabiting, 30-57. Phisalix, experiments of, on venom with alternating currents of high frequency, 165. on effects of enianations of radium on venom, 166. variations in local effects of venoms, 176. venom of Cryptobranchus japonicus, 317. ,, poison from bee-venom prepared by, 283. ,, researches of, on glands of snakes, 147. and Bertrand, experiments on immunity of hedgehog to venom, 226. preparation of toad-venom, 319. ' Phoorsa. See Ecliis carinatus. Phrynolysin, 320. ,, extracted from skins of toads, 320. Physiology of experimental poisoning, 170. Physostonii, 307. Pig, destruction of vipers and rattlesnakes by, 125, 222, 226. ,, immunity to snake-venom due to defence provided by adipose tissue, 222. „ serum, devoid of antitoxic substance, 222. Pigeons, vaccination against rattle-snake-venom, 241. ,, killed by causing them to ingest venom, 180. Pinto, Col. S., on immunity to inoculation, 238, 239. Platurus, 140. ,, colubrinus, 141. ,, laticaudatus, 141. ,, muelleri, 141. ,, scMstorhynchus, .141. Plectognathi (family Gymnodontes), 305. Pliny on salamanders, 312. ,, treatment of poisonous snake-bites, 259. Plotosus, 308. ,, lineatus, 308. ,, ,, poison-apparatus of, 308. Plutarch on snake-charmers, 228. Poison-apparatus of Cottus, 293. Murmna, 309, 310. ,, Plotosics lineatus, 308. ,, Scorpcena, 294. ,, snakes, 8. Synanccia, 291. Trachinus (weevers), 297, 298, 299. ,, venomous fishes, 289. Poison-fang, 8. „ action of, 148. ,, of Proteroglypha grooved, 4, ,, Viperidce canaliculate, 5. Poison -gland of Hymenoptera, 281, 282. 394 VENOMS Poison-gland of non-venomous snakes, 217. venomous snakes, 10, 11, 12, 13 Polistes, 285. Poinpilns, 285. Pondicherry, collection of venom at, 15G-158. Hospital, collection of venom, method, 362. „ public notice in, re capture of poisonous snakes, 360. Prairie rattle-snake, 120. See also Sistrurus catenatus. Pravaz syringe, injection of serum with, 263. Precipitins of venoms, 202. Frionurus, 301. Proscher on extraction of phrynolysin from skins of toads, 320. Proteids, extraction from snake-venom, 163. Proteolytic action of venoms, 204. " >> )> extent and limitations, 205. ProteroglypJia (group of Goluhridce), 4. ,, bite rapidly produces general intoxication, 168. ,, poison-fangs of, grooved, 4. sub-families of, 4. See also HijclrophiincB ; Elapince. Proto-albumoses, active principle of snake-venom, 164. ,, separation from snake-venom, 162, 163. Pseudechis, 87. ,, venom of, experiments on, 162. >> n ingestion by rats harmless, 181. ,, australis, 88. ,, cupreus, 88. „ darwiniensis, 88. ,, ferox, 88. ,, microlepidohis, 88. ,, papuanus, 88. piorphyriacus (black snake), 88. " >> >) ,, bite dangerous, 100. " >' ,, secretion of, 149. ,, scutellatus, 88. Pseudelaps, 84. ,, diadema, 85. ,, liarriettcB, 85. ,, krefftii, 85. ,, muelleri, 84. ,, sqiianmlosus, 84. , , sutherlandi, 86. ,, warro, 86. Pseiulocerastes p)ersicus, 47. Psylli, Egyptian charmers and healers, 228-229. ,, Roman charmers and healers, 228. i> ). ,, Lucan on, 240. Pterois, 293, 295-296. Pufi adder, 69. See also Bitis arietans. Putrefaction, rapid, following death from snake-bite, 211, 212. Pyramids, viper of (Echis carinatus), 76. INDEX 395 Queensland, mortality from suake-bite slight in, 100. Rabbit, experiments on, demonstrating neutralisation of venom by antitoxin, 255. minimal doses of various venoms lethal for, 173, 174, 175. ,, vaccination against cobra-venom, 243. Bascasse, 296. Rat, P., on common viper's bite, 358. „ ingestion of venom of Pseudechis harmless to, 181. minimal doses of various venoms lethal for, 174. Rat-serum, bacteriolytic action of venom not comparable to, 208. Rattle-snake, common, 125. See also Crotalus dimssus. dog-faced, 124. See also Crotalus terrificus. , ground, 120. See also Sistrtirus miliarius. horned, 129. See also Crotahis cerastes. Pacific, or mottled, 124. See also Crotalus confluentus. prairie, 120. See also Sistrurus catenatus. Texas, 124. See also Crotalus scutulatus. venom, vaccination of pigeons against, 241. Red Sea, Naseiis found in, 301. Reichert on chemical constituents of venom, 160. Renaux, P., on bites from Crotalus horridus, 355. Rennie, Major S. J., case of bite of Bungarus cceruleus, 837. Reptiles, toxicity of blood in, 217. Respiratory centres, nerve-cell of, attacked by albumose of snake-venom, 162. RMnhoplocephahts, 95. ,, bicolor, 95. Bhynchelaps, 97. ,, ausiralis, 98. ,, bertholdi, 97. ,, .fasciolatus, 98. ,, semifasciatus, 98. Richards on fatal results of experimental ingestion of venoms, 180. Richet, C, congestin from Anemoiie scuUata prepared by, 270. ,, thalassin, from Anemone scultata prepared by, 269. Ringhals slang, 63. See also Sepedon hamachates. River-jack viper, 73. See also Bitis gabonica. Rogers, Major L., experiments on action of venom on nervous centres, 186. researches of, on glands of snakes, 147. Romans, snake-charmers' customs among, 228. Lucan on, 240. Roudot, Natalis, on Hindu snake-charmers, 229. Russell, on the venom of daboia (Vipera russellii), 46. Sachs, on relation of toxins to antitoxins, 254. Salamandarin, 316. See also Salamandrine. Salamander, Japanese, 317. See also Cryptobranchus japonicus. „ venom of, closely analogous to that of toad, 321. ,, potency exaggerated by the ancients, 312. Salamanders and toads most dreaded by ancients, 312. 396 VENOMS Salamandra atra (black salamander), 313, „ maculosa (spotted salamander), 813, 314. Salamaudridine prepared from venom of salamanders, 317 Salamandrine, prepared from venom of salamanders, 317. Sahva of Heloderma ho^ridtcm sometimes toxic, sometimes harmless, 323. „ venomous, of non-poisonous snakes, 214. Sangis, name of snake-charmers of Bengal', 229. SSo-Paulo (Brazil), laboratory for production of antivenomous serum at, 248, 252 bcales, arrangement of, on heads of poisonous snakes, 14 15 Scolopetidra, 280. ScolopendridcB, bite of, 281. Scorpmia, 288, 289, 293. ,, poison-apparatus of, 294. diabolus, 293. grandicomis, 293. ,, porcus, 294. Scorpio occitanus, 277, 278. Scorpion, blood of, antitoxic, 279. ,, manner of stinging, 277. poison, 278. » affinities with that of Colubridoi, 278. >. neurotoxin of, 278. Scoipionidea (scorpions), 276. Sea-snakes, 131. See also HydrophiincB. „ (Hydrophis), venom from, 360. Sepedon hczmachates (spitting snake or ringhals slang), 63. >» >> bite of, cure, 337. " " venom of, purulent ophthalmia discharged by spitting, 63, 64. „ " ," " " » caused by projection of, 62. 180. berous membranes, local effects on, of cobra-venom, slight, 179. " " '> I) venoms <3f "FipmtZffi, severe, 179. Serph, collection of venom, 156. Serranus, 304. ,, ouatabili, 304. Serum, antivenomous, antineurotoxic, 250, 251. " " potency against cobra-venom, 250, 251, 252. " " ti^eatment of bites of poisonous snakes, 326. " " i> yellow fever, 184. , method for measuring power of, 256, 257. " >' >> M >, in vitro, 202. " >) neutralisation of snake-venom by, 253-258. " " " >' .1 experiments showing necessary pro- portions to effect, 254, 255. i> >, polyvalent, 251. " >' I) prepared from horse, 251. .1 preparation of, 246. " ,1 test-solutions, 247. " " >i at Pasteur Institute, Lille, 245-248. '» II special laboratories, 248, 252. INDEX 397 Serum, antivenomous, preventive power tested by intravenous injection, 246. rules respecting proportions of quantity to be administered, 266, 267, 268. specificity of, 248. Calmette's, in treatment of cobra-bites, 363, 364, 365. tberapeutics, antivenomous, 241-252. technique of, 262-265. See also Snake serum. Serums, specific against coagulant venoms, 192. Sewall on vaccination of pigeons against rattle-snake venom, 241. SiluridcB, 307, 308. Sihirns glanis, 308. Sistrurus, 110, 120. catenatus (prairie rattle-snake, or massasanga), 120. ,, miliariits (ground rattle-snake), 120. ,, 7-avus, 120. Skin, marks produced on, by bites of different species of snakes (venomous and non- venomous), 10. Smell, loss of, following bite of viper, 178. Smith, MacGarvie, researches of, 149. on chemical constituents of venom, 160. and Martin, C. J. , on local and general eSects of albumoses derived from snake-venoms, 163. Snake-bite, death from, rapid putrefaction following, 211, 212. hypo-leucocybosis accompanying, in lethal cases, 211, 212. " mortality from, 2, 3, 38, 57, 100, 261, 363. „ non-lethal, suppuration following, 212. poisonous, treatment in domestic animals, 265. ,, men and animals, 259. See aZso Serum therapeutics, antivenomous. Snake-charmers, 228. deaths from bites, 234. Egyptian, 228-229. ,, employment of Naja haje for performances, 61. Indian, 229-234. Libyan, 228. Roman, 228. ,, safety in skill, 234. Snake-serum combined with snake-venom does not destroy red corpuscles, 220. ,, dissolution of red corpuscles by, 219. Snake-venom, action on heart, 184. „ kidney, 183. ,, liver, 182. lungs, 184. ,, nervous centres, 185, ,, spleen, 183. ,, striated muscles, 184. activity greatest after prolonged fasting and after moult, 176. aids digestion of prey, 213, 214. VENOMS Snake-venom, antagonism between coagulant and anticoagulant kinds, 194. antidotes to, before absorption, 260, 261. „ artificial introduction into egg of fowl, effect on embryo, 214. bacteriolytic action, 20G. >» •' substance in, peculiarities of, 207, 208. chemical study of, 159. „ collection of, 147, 152-158. >' >> in French Settlements in India, 359. combination with lecithin, 254. „ combined with snake-serum does not dissolve red corpuscles, 220. complex effects on tissues, 215. ,, complexity of means of defence' against, 215. „ cytolytic action, 206. ,, • diastasic action of, 212. „ dried, 149. ,, effects of, in non-lethal doses, 177. extraction of, by Hindus, 233. >> >> from Alcatifa, for inoculation, 239. freshly collected, 149. ). hypoleucocytosis following fatal dose, 216. ,, immunity to, 2'22. >> .) from inoculation, 234-235. >» >. of herons to, probable, 226, 227. „ ingestion of, fails to secure immunity to lethal dose, 214, 215. >> ,. harmless, 214. ,, lethal to snakes of other species, 219. „ neutralisation by antitoxin, 253-258. " " injection of antitoxic serum, second step in treatment after bite, 262. „ no strict ratio between dose inoculated and time elapsing till death, 177. ,, parallelism between neurotoxic and htemolytic action, 255. „ prevention of absorption first step in treatment after bite,'262. „ produces acute inflammation of mucous membrane, 180. protective role of leucocytes against, 216. ,, proteolytic action, 204. ,, re-constitution, method of, 257, 258. secretion of, 147-152. ,, temperature lowered after fatal dose, 216. ,, toxic conditions of, 151. vaccination against, 241. ,, variations in local effects of, 176. Snakes, coloration of, 15, 16. M M subject to biological laws of mimicry, 15, 16. ,, cranial skeleton of, 6. ,, dentition of, 6. ,, moulting of skin, 16, 20. ,, non-poisonous, arrangement of scales on head of, 14. 5, poison-glands in, 217. ,> venomous saliva of, 214. INDEX 399 Snakes, non- poisonous,- withstand large doses of venom, 172. ,, poisonous, all species caruivorous, 17. arrangement of scales on head of, 15. ,, artificial feeding of, 17, 18. _^ • bite of, danger diminished by clothing or other means of protection, 170. ,, blood of, toxicity, 217. characterised by special arrangement of facial bones, 6. deaths from, in Queensland, 100. devoured by herons, 227. different species should not be placed in same cage, 219. difficult to distinguish froni non-venomous, 2. digestion aided by venom, 21-3, 214. dread of destruction of, cause of excessive mortality from snake-bite in India, 2. geographical distribution of, 2, 3. habits of, 17. • health authorities' notices respecting, in Australia, 100. kept in captivity, 61, 72, 125, 156, 223. ,,. method of capture, 20, 21. stri^ring and seizing prey, 17. ,, muscular apparatus of head of, 11, 12, 18. ,, „ of Africa, 57-81. Asia, Dutch Indies and Philippine Islands, 30-67. Australia, 81-100. ,, Europe, 22-29. Malaysia, 81. New Guinea, 81-100. „ South Sea Islands, 81-100. „ ,, Sunda Islands, 81. poison-apparatus of, 8. ,, poison-fangs of, 8. poison-glands of, 10, 11, 12, 13. succumb to venom of other species, 173. teeth of, difference in arrangement and dimensions of various species, 9. treatment of bites from, in French Settlements in India, 359'. unaffected by enormous doses of their own venom, 172. J J unknown in New Caledonia, 100. ,, New Zealand, 100. victory of mongooses over, in combat, due mainly to natural agility, 225. ,, worship of, 2. ,, extant in India, 2. Solenoglypha, 109. ,, bite produces important local disorders, 168. ,, marks produced on skin by bite of one of, 10. Sonoran coral-snake, 102. See also Elaps euryxanthus. South Sea Islands, poisonous snakes of, 81-100. Sparrows, effect of venom of Heterometrus maurus on, 279. Sphasrechimos granulans, poison from pedicellarise, 273. Spinal cord, comparative actions of venoms of CohibridcB and ViperidcB on, 185, 186. 400 VENOMS Spiders. See Araneida. ' Spitting snake, 63. See also Sepedon haimachates. Spleen, action of venom on, 183. Sponge-divers, malady of, 272. Squainipi7mes, 304. Stings (wasp- or bee-), treatment for, 286. Stomach, acute inflammation of gastric mucous membrane produced by ingestion of venoms of ViperidcB, 180. Slrongylocentrotus lividus, poison from pedicellarise of, 273. Stryclinine, injection of, of no value as antidote against snake-venom, 261. Sunda Islands, poisonous snakes of, 81. Superstitions, native methods of inoculation full of, 239-240. Suppuration following non-lethal snake-bites, 212. Surucucu or bushmaster, 112. See also Lachesis mutus. Sutherland, Surgeon-Captain, bite from Echis carinatus, 348. Sydney, laboratory for production of antivenomous serum at, 248, 252. Synanceia, 288, 289, 290. ,, poison-apparatus of, 291. ,, bracJdo, 291. Syncope, following inoculation of venom of Synanceia brachio, 292. Teleostei, 290, 305, 307. Temperature, effect of, on venoms, 161. Tetrodon, 290, 305. ,, riibi-ipes, 306. ,, stellatus, 306. Teuthididce, 301. Teuthis, 301. Texas rattle-snake, 124. See also Crotahis scutulahis. Thalassin, poison from Anemone scultata, 270. Thalassophis, 133. ThalassopUryne, 288, 303. ,, maculosa, 303. ,, reticulata, 302-303. Thuau on bites from European vipers, 342. Tidswell, P., on venom of Ornithorhynclms, 324. Tiger-snake, 95. See also Notechis scutatus. Toad, common, 318. ,, green, 318. ,, musical, 318. ,, and frog, distinctions between, 318. ,, ,, salamander, much dreaded by ancients, 312. „ venom of, 318, 319. ,, active principles of, 319, 320. „ ,, closely analogous to that of salamander, 321. „ ,, preparation, 319. ,, ,, exaggerated by the ancients, 312. Trachinidai, 297. Trachinus (weever), 288, 289, 297. INDEX Trachimis (vveever) poison-apparatus of, 297, 298, 299. ,, araneus, 297. ,, draco, 297. ,, radiatus, 297. ,, viper a, 297. Travers, P. M., on bite from Bitis arietans, 350. Trichloride of iodine modifies or destroys venoms, 164. Triglida, 290. Trigonocephalus, bites from, 352, 355. TrivieresJirus graviineus, 55. See also Lachesis graniineus. ,, riukiami,s, 53. See also Lachesis flavoviridis. Triodon, 805. Triton cristalus, 313. ,, marmoratus, 313, 314. Tropidechis, 94. „ carinatus, 94. Tropidonotiis matrix (grass-snake), venogen of, 151. Trypanosomes, dissolution by cobra-venom, 207. Tubriwallahs, snake-charmers of Bengal, 229. Tunis, snake-charmers of, 228. Tuxpan, natives of, inoculation methods, 235-237. Ueodela, salamanders belong to order of, 312. Urtitu, 115. See also Lachesis neuwiedii. Vaccination against cobra-venom, 242. ,, snake-venom, 241. Van Denburgh, J. , observations on Heloderma horridum, 323. Vatuas, method of inoculation of, 239. Venomous secretion, histology, 151. de Villiers, on common viper's bite, 357. Viper, common, of Europe. See Vipera berus. ,, horned, bite from, 349. ,, inoculation of professional catchers of, in France, 234. Vipera, 43. „ zoological characters of, 23, 24. ,, ammodytes, 29, 69. ,, as]}is (asp, or red viper), 27, 28. ,, ,, bite from, cure, 339. ,, ,, poison-cells, 151. ,, berus (common viper, or adder), 25, 26. ,, devoured by hedgehogs, 222, 226. ,, ,, mortality from bite, 27. ,, ,, venom of, chemical constituency, 149, 160. ,, ,, ,, immunity of hedgehog to, 226. ,, ,, ,, uncertain coagulant action on blood, 189, 190. ,, latastii, 28, 69. ,, lebetina, 44, 69. 26 402 VENOMS Vipei-a raddii, 44. „ renardi, 44. ,, rjissellii (daboia, or Russell's viper), 45, 46. muscular apparatus of head of, 11, 12. poison-gland of, 11, 12. protection against, adopted by natives, 46. venom of, coagulant action on blood, diminished when heated, 191. ,, extremely potent, 46. ,, dose lethal for rabbit, 175. ,, ingestion causing death, 180. ,, superciliaris, 69. ,, ursinii, 24, 25, 44. ViperidcE, 5, 43, 66. ,, bites of, local gangrene resulting from, 177. ,, characteristics of, 5. ,, geographical distribution, 6. ,, poison-fangs canaliculate, 5. ,, species of, bite produces grave local disorders, 168. ,, sub-families of, 6. ' See also Viperina, Crotalince. ,, venoms of, absorption by digestive tract sets up acute inflammation of gastric mucous membrane, 180. action on nervous centres weak, 185, 186. comparison of coagulant action on blood of various species, 190. easily destroyed by heat, 161. heemolysing power, weak, 199. lethal efTects on mammals, 171. neurotoxin present in those of some species, 249. non-dialytic, 161. produce coagulation of blood, 179, 188, 189. ,, hsemorrhagic injections of peritoneum, 179, 180. recovery after non-lethal doses, slow, 177. ,, ,, ,, followed by loss of sight, smell, or hearing, 178. recovery after non-lethal doses complicated by visceral haemorrhages, 177, 178. resemblance in action of that of Japanese salamander to, 317. ,, ,, ,, OrnithorhyncJms to, 324,. richness. in haemorrhagin, 249. Viperin, chemistry of, 130. ViperincB, 43, 66, 101. See also Atheris, Atractaspis, Bitis, Caiisus, Cerastes, Echis, Pseudocerastes, Vipera. ,, characteristics of, 6. Viscera, haemorrhages from, complicating recovery from bites of Viperida, 177, 178. ,, hypersemia of, caused by fatal bite of species of Colubridce, 171. Wall, chemical constituents of venom, 160. Waller, fatal instance of rapid poisoning from bite of Naja liaje, 60. Waltei-innesia, 64. INDEX 40S Walterinnesia agyptia, 65. Wasp, sting of, death from, 283. „ ,, remedies for, 286. Weevers, 297. See also Trachinus. stings of, 298, 299. Wehrmann, on diastasic actions of venoms, 212, 213. ,, experiments on ingestion of venom, 214. Wertheimer, Austrian naturalist, fatally bitten by coral snake, 108. Witch-doctors, remedies of, 237, 238, 239. Wolfenden, Norris, chemical constituents of venom, 160. Wright, 0. B., observations on Heloderma liorridum, 323. Yellow fever, treatment by antitoxin of venom, 184. Zebvos, Dr. S., malady of sponge-divers, 272. A ty \ r / /