338 



ORDERS OF REPTILES— SERPENTS 



mouth, well forward, and while not in use they 

 lie up against the roof of the mouth. The tongue 

 of a serpent is very extensible, and capable of 

 being thrust out fully half the length of the head. 

 Its greatest use is in examining food, or possible 

 food. From the fact that when travelling the 

 tongue is so frequently thrust out, even when 

 there is no excitement, it seems highly probable 

 that it is used to detect vibrations in the air. 

 (R. L. Ditmars.) The tongue is forked, and 

 being entirely harmless, its sole use in defence is 

 to threaten and intimidate its enemies. 



The lower jaws are loosely attached to the 

 skull, and to each other at their front end, by 

 ligaments so elastic that when prey is being 

 swallowed, the gape expands to enormous pro- 

 portions. Mammals, birds and fishes to be 

 swallowed are always seized head first, in order 

 that the limbs, and also the feathers or scales, if 

 there be any, will lie snugly against the body. 

 Frogs and toads are usually taken hind feet 

 first. The lower jaw is forced forward and over 

 the animal, always one side at a time, as far as 

 it will go ; and when the teeth are inserted, that 

 side is drawn back. The upper part of the head 

 slides forward as far as possible, one side at a 

 time, to match the lower jaw. Sometimes it 

 seems as if the lower jaw will be torn loose from 

 the head. Often after an animal has vanished, 

 the jaws are a bad misfit, and do not come back 

 into shape for half an hour. 



The skin stretches like India-rubber, and 

 over a heavy meal the scales are widely separated. 

 The manner in which serpents feed in a wild state 

 is certainly one of the most cruel processes of 

 Nature. 



The eyes of a serpent have no lids, and the 

 eyes never close; but they are protected by a 

 thin and perfectly transparent section of the 

 outer skin, or epidermis, which is shed and re- 

 newed periodically. 



The epidermis, or outer skin, is completely 

 renewed about three times per year. To free 

 itself from the old skin, the serpent usually 

 crawls through a small aperture, the edges of 

 which catch the old skin at the head and hold 

 it fast while the owner crawls out of it. The 

 first intimation of an impending change of 

 epidermis is found in the dull appearance of the 

 eye, over which a glassy film seems to be form- 

 ing. Strange to say, even the eye sheds its outer 



surface, and emerges clear and brilliant. Most 

 snakes shed their skins about three times a year. 



A serpent is always most beautiful immedi- 

 ately after it has shed its epidermis, for then its 

 colors are brightest and most iridescent. In 

 captivity it often happens that the atmosphere 

 in which a snake lives is not sufficiently moist 

 to enable the old skin to loosen and be cast off. 

 In such cases, if the serpents are non-venomous 

 species, the owner must moisten the old skin, 

 and peel it off by hand, or with forceps. 



Reproduction. — Some snakes lay eggs, with 

 soft, tough shells, that are hatched by the sun. 

 A serpent which develops in an egg of this sort 

 is provided with a special, temporary tooth, set 

 on the tip end of its jaw, with which it easily 

 punctures the shell sufficiently to escape. Oth- 

 ers do not develop eggs with shells, but instead 

 retain their eggs in their own bodies until the 

 young are fully developed. Finally they are 

 brought forth, each fully enclosed in a thin, 

 membranous sac, which the little serpent quick- 

 ly bursts. Snakes that lay eggs are called o-vip'- 

 a-rous, and those that bring forth their young 

 alive are called vi-vip'-a-rous. 



Although serpents are cold-blooded animals, 

 they reach their highest development in warm 

 latitudes, and in regions of arctic cold they do 

 not survive. In the temperate zone and the 

 tropics, Nature has fitted them for life upon 

 the ground, in the water, and in the tree-tops; 

 and they inhabit swamps, uplands and deserts. 

 They live under stones and logs, in hollow trees 

 and stumps, and in holes in the earth ; and they 

 seldom attack man wilfully, and without provo- 

 cation. 



Food of Serpents. — In a wild state, snakes 

 feed chiefly upon frogs and toads, fish, other 

 snakes, small birds and mammals. Large ser- 

 pents feed upon mammals of all sizes, up to small 

 deer and goats. Water-snakes feed chiefly upon 

 fish and frogs. Land species find frogs, toads 

 and small lizards their cheapest prey, but the 

 extent to which snakes feed upon each other is 

 quite surprising. For example, the king cobra, 1 

 a large, athletic, and very deadly land-serpent 

 of the Malay Peninsula, feeds exclusively upon 

 other snakes and lizards, and while a greedy 

 feeder upon what it prefers, it persistently re- 

 fuses all other food. During the three years that 

 1 Na'ja bun-gar'us. 



