Australia, with its Black and Tiger-snakes and the Death-adder, possesses snakes as venomous as the cobra, which the first-named species approach in their capacity to inflate their necks, though to a less degree. The Tasmanian Black Snake, as it glides swiftly, as though sailing, across open grass-land, with the midday sun scintillating on its 7-foot stretch of jet-black, highly polished scales, its head and expanded neck threateningly elevated some 18 inches above the ground, is certainly a most impressive sight.
One very distinct group of the front-fanged section which demands brief notice is that of the Sea-snakes. These are readily distinguished by their especial adaptation to a marine existence, their much-compressed, oar-like tails constituting powerful propelling organs. In contradistinction to the terrestrial snakes of the same group, the inferior scales, not being required for terrestrial locomotion, are little if any larger than the upper ones. All the species are highly venomous; they feed chiefly upon fish, and are distributed throughout the tropical seas. The larger species rarely exceed 5 or 6 feet in length, and the majority are much smaller. Many species are noted for their conspicuous colouring, which most frequently takes the form of distinctly contrasting bands. All the members of this group are viviparous.
Photo by J. W. McLellan] [Highbury.
RATTLE-SNAKE.
The rattle-snake is pre-eminently noted for its power of fascinating birds and the smaller mammals.
The last and most highly specialised section of the Snake Tribe is that of the Viper and its allies, collectively known as the Viperine Family. In all the representatives of this group the hinder upper jaw-bone is so loosely articulated that it is capable of erection at a right angle to the horizontal plane of the skull, the gape of the mouth being in consequence abnormally wide. The teeth in the upper jaw are reduced to a single anteriorly situated pair of tubular poison-fangs, with which, when striking its prey, the snake deals a direct stab. The head in the majority of the Viperine Snakes is flattened and triangular, nearly resembling in contour the symbolic ace of spades. The body is usually relatively thick, and the tail short and stumpy. The vertical pupil of the eye denotes nocturnal habits. All the members of the section are venomous.
The Viperine Snakes are usually divided into two groups. The first contains the Typical or Old World Vipers, and includes, in addition to the Common Viper, the Cerastes or Horned Viper of Egypt, and the large and most repulsive and deadly African Puff-adder. The Common Viper or Adder, the only poisonous British snake, has a very extensive geographical distribution, extending throughout Europe and Asia as far east as the island of Saghalien, and northwards to the Arctic Circle. The Horned Viper of the Sahara and North Africa is one of the most venomous of living serpents. Lying buried beneath the sand, with only its head above, it will spring aggressively at any animal which passes by, and the action of its venom is so rapid that a horse or man bitten by it usually dies within half an hour. In colour the horned viper closely resembles the sand or stony wastes among which it lies. The most remarkable feature in this snake is the presence of two elevated horn-like processes immediately above the eyes, which are most prominent in the male. The species has frequently been on view at the Zoological Society's Gardens. On one occasion an ostensible example was purchased and deposited in the Reptile-house, which proved on nearer investigation to be a base imposition. A common desert-viper had been cleverly manipulated by the deft insertion of suitably shaped splinters of wood into its head, so that it resembled the rarer horned variety. The Puff-adder, the largest member of its tribe, may attain to a length of 6 feet or more, and is distributed throughout the African Continent. Its thick body is almost triangular in section, the head very large, flat, and bluntly rounded anteriorly, while the eyes have a particularly fierce, stony, and repulsive aspect. In colour individuals vary considerably, but there is generally a chequered pattern of reds, browns, and greys, disposed in the form of darker and lighter alternating crescent-shaped bands along the back. The poison of this snake is nearly as virulent as that of the horned viper, and is commonly used by the African bushmen for poisoning their arrows.
The Viperine group is abundantly represented in the New World, where its members differ from the typical Old World species in sundry anatomical points, one of the most conspicuous features being the presence of a distinct depression or pit in the surface of the head between the nostril and the eye on either side. On this account they are distinguished by the title of Pit-vipers. Among the more familiar representatives of this group are the Rattle-snakes, the Fer-de-lance, the Bush-master, and the Copper-head or Mocassin-snakes. All these are notoriously venomous, fatal effects from bites received by human subjects being of frequent recurrence. The Rattle-snakes are especially distinguished by the peculiar, loosely jointed, horny appendage to their tails, by the rapid vibration of which, when disturbed, they fortunately give timely notice of their presence. In the young individuals this rattle is only represented by a single button-like knob, additional loose, hollow, horny rings being added between it and the scaly termination of the tail as age increases. In full-grown examples the horny rings composing the rattle may number as many as twenty or more, though, owing to the war of extermination incessantly levied against these reptiles in all civilised areas, it is rarely that such elaborate rattle-bearers are now met with. The rattle-snake, in the more northern districts of its distribution, hibernates in the winter, often congregating together in great numbers for the sake of the mutual warmth. In the earlier days certain caves were famous as the retreats into which not only hundreds but thousands of the reptiles would congregate from the country round for their winter's slumber. At such times hunting-parties were specially organised for their wholesale destruction, and accomplished much towards reducing their ranks to their present numbers.
