190 THE LIVING ANIMALS OF THE WORLD 
Snakes, 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 RINGED and the SMOOTH SNAKES — this 
number, by a coincidence, being identical with that of the Lizard Tribe indigenous to the 
same islands. Many of the smaller species are little over 1 foot long, while the huge Pythons 
and the Anaconda may attain to or exceed 30 feet. Regarding their habits, some are purely 
terrestrial, 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 débris, 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 
Amphisbenas 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 upper or lower jaw. The 
food of the blind-snakes 
consists largely of ants and 
the larve of beetles and 
other insects which lead a 
subterranean life. Although 
: , spending the greater portion 
Photo by W’. P. Dando, F.Z.S.] [Regent’s Park of their existence under- 
ground, they occasionally 
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 steps 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 Tribe, would seem at first sight to be altogether unwarranted. In one essential 
character, however, they agree very remarkably. In both groups the bony skeleton exhibits 
a far more generalised structural 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 
kinds — such as the Vipers, with their death-dealing poison-fangs — have been evolved. 
The 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 in the form of poison-fangs. The body is usually more or less compressed, and the 
BOA-CONSTRICTOR READY TO STRIKE 
The neck, thrown back in one or more loops, can be projected, with immense force and lig htning- 
, ; jected, i ig 
like rapidity, to strike or seize an intended victim. 
