SNAKES 241 



the snake lies in wait in the dense underwood, and should one of them 

 approach too close, it darts with lightning speed upon its victim, seizes it 

 in its jaws, and entwines it in two or three coils of its pliant body, after 

 which it seizes the prey by the head and slowly forces it down its throat. 



Of the gigantic snakes (Pythons and Boas) of the tropical zones the 

 following species are frequently kept in zoological gardens and 

 menageries : 



The Boa -Constrictor is a native of the eastern and northern 

 parts of South America. It is magnificently coloured, corresponding 

 in this respect with the variegated vegetation of its habitat (compare 

 with parrots, humming-birds, etc.). The ground colour is reddish- 

 grey, with broad darker longitudinal stripes and spots of lighter colour. 

 A full-grown snake, which reaches a length of more than 20 feet, is said 

 to be able to kill and devour animals of the size of deer (enfolding them 

 in the coils of its pliant body). Its food, however, consists principally of 

 birds and small mammals. It was formerly worshipped by the natives 

 as a deity. 



Of equally gigantic size and rich colouring is the Anaconda (Eunectes 

 murinus), also a native of South America. It lives by preference in and 

 near the water. In places where ponds, streams, or lakes dry up com- 

 pletely during the hot season this snake buries itself in the mud and 

 enters upon a summer sleep. 



The Python (Python molurus) inhabits marshy districts in the East 

 Indies. The colours of its scaly coat resemble those of the tiger's skin 

 (light brown with irregular, dark four-cornered spots; compare with 

 leopard). It attains to a length of above 20 feet. This and the two 

 preceding species are very dangerous to man. 



2. Venomous Snakes. 



The Viper (Pelias berus). 



(Length : female up to 26 inches, male up to 32 inches.) 

 This is our only native poisonous snake, and should therefore be 

 known to everyone. 



A. Distinguishing Characters. 



The viper may be distinguished from all other native snakes by the 

 following characters : The flat triangular head, which is distinctly 

 marked off from the neck ; the thick, stout body ; the short tail ; and the 

 presence of scales upon the head as well as scutes. The scales of the 

 back, which are " carinated," i.e., have a small prominence or crest in 

 the middle, serve to distinguish it unmistakably from the smooth snake, 



