Venoms: Venomous Animals and Antivenomous Serum-therapeutics. A. Calmette
XVII. VENOMS IN THE ANIMAL SERIES (continued) .
A.— Teleostei.—Acanthopterygii.
CHAPTER XVIII. VENOMS IN THE ANIMAL SERIES (continued) .
3.— BATRACHIANS. LIZARDS. MAMMALS.
A.— Naja tripudians (India and Indo-China) .
PART I.
CHAPTER I.
GENERAL NOTES ON POISONOUS ANIMALS—POISONOUS SNAKES: GENERAL CLASSIFICATION AND ANATOMO-PHYSIOLOGICAL CHARACTERS.
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, salamander); 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 teeth 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, Cœlenterates, 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 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 Scarabæus and the flowers of the lotus to represent Immortality!
At Rome epidemics ceased when the snake sacred to Æsculapius 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 Krait, 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; but in North America the Rattle-snake and the Moccasin are especially deadly.
In France the Common Viper abounds in Jura, Isère, Ardèche, Auvergne, Vendée, and the Forest of Fontainebleau. Three hundred thousand have been killed in twenty-seven years in the Department of Haute-Saône 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.—General Classification of Poisonous Snakes. Their Anatomo-physiological Characters.
Poisonous snakes are divided by naturalists into two great Families, the Colubridæ and Viperidæ, distinguished from each other by certain anatomical characters, and especially by the dentition.
The Colubridæ resemble harmless snakes, which renders them all the more dangerous.
They are divided into two groups: Opisthoglypha (ὄπισθεν, behind; γλυφὴ, a groove) and Proteroglypha (πρότερον, before; γλυφὴ, 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 Homalopsinæ, having valved nostrils, placed above the snout.
B. The Dipsadomorphinæ, in which the nostrils are lateral in position, and the dentition is highly developed.
C. The Elachistodontinæ, 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 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 Homalopsinæ are aquatic; they bring forth their young in the water, and are met with 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