588 



The Living Animals of the World 



Sniilces, like lizards, are most abundant in tropical countries, the Indian and Malay regions 

 in particular being richest in numbers and varieties. The British Islands support but three 

 representatives of the class — the Adder, the Common Einged and the Smooth Snakes — this 

 number, by a coincidence, being identical with that of the Lizard Tribe indigenous to the 

 same islands. JManv of the smaller species are little over 1 foot long, while the huge Pythons 

 and the Anaconda may attain to or exceed 30 feet. Eegarding their habits, some are purely 

 terrestiial, frequenting the rocks or sandy deserts, or even burrowing beneath the earth's 

 surface. Others are essentially arboreal, many amphibious, and some, like the Turtles among 

 the Chelonians, entirely marine. As with the Lizards, the majority of snakes lay eggs enclosed 

 within a white leathery shell, while with a considerable number the young are brought forth 

 alive. The eggs, deposited in the earth, sand, or among vegetable debris, are usually left to 

 be hatched by the heat of the sun. In the case of the Pythons, however, they are incubated 

 by the parent. 



A small group of snakes which is usually placed at the head of the series in systematic 



classifications share the sub- 

 terranean habits of the 

 Amphisbsenas among the 

 Lizards ; and the eyes being 

 rudimentary and functionless, 

 they are commonly known as 

 Blind-snakes. A structural 

 peculiarity which separates 

 these singular reptiles from 

 all other members of the 

 Snake Tribe is the entire 

 absence of teeth from either 

 the u^iper or lower jaw. The 

 food of the blind-snakes 

 consists largely of ants and 

 the larvfB of beetles and 

 other insects which lead a 

 subterranean life. Although 

 sjiending the greater portion 

 of their existence under- 

 ground, they occasioHally 

 come out upon the surface, 

 such migrations more gener- 

 ally taking place during 

 showery weather. About 100 species of blind- snakes are known, and are mostly confined to 

 tropical countries. One small worm-like form occurs in Greece and the adjacent islands, its 

 range extending through a considerable area of South-western Asia. 



The step from the small worm-like Blind-snakes, with their functionless eyes and under- 

 ground habits, to the Boas and Pythons, the largest and most highly organised members of 

 the Serpent Trilje, would seem at first sight, to be altogether unwarranted. In one essential 

 character, howe\-er. they agree very remarkably. In both groups the bony skeleton exhibits 

 a far more generalised siructural plan than in any of the succeeding ones, so that they may be 

 regarded as more nearly resembling the primitive stock from which the other more specialised 

 kindb-^sucOi as the Vipers, with their death-dealing poison-fangs— have been evolved. 



I he Pythons and Boas, or Boa-constrictors, as they are popularly known, belong entirely 

 to the non-venomous section of the Snake series. The teeth, forming two rows in the upper 

 jaws, gradually decrease in size from, before backwards, and none of them are grooved or 

 modified m the form of poison-fangs. The body is usually more or less compressed, and the 



[RiycU'a Park. 



Fhoto hi) II". F. Daiido, F.Z..S.] 



BOA-COXSTEICTOR READY TO STRIKE. 

 The neck, thrown tack in one or more loops, can be projected, villi immense foice and lightn 

 like rapidity, to stiike or seize an intended victim. 



