THE SNAKES 325 



ing itself in the sand. At night it comes forth to seek 

 the trails of small mammals; finding a likely spot, it lies 

 flattened and motionless, the anterior part of the body 

 doubled into an S-shaped loop. That silent form is wide 

 awake and watching. Woe betide the luckless rodent 

 that passes it ! A dart of the snake seals the fate of the 

 victim, which, pierced by the terrible fangs, seldom utters 

 as much as an agonized squeal. 



The pattern of the Puff Adder is characteristic. A 

 freshly-shed specimen generally shows sooty black 

 chevrons, separated by cream-colored crescents. There 

 are, of course, variations in the body hues ; on some snakes 

 the crescents are dull buff and the chevron markings 

 dark brown or gray. The popular title comes from the 

 common habit of the true vipers — that of hissing vio- 

 lently with each inhalation and expulsion of the breath, 

 but a habit particularly vociferous with the present ser- 

 pent. 



Another of these hideously-ugly snakes is the Gaboon 

 Viper, B. gabonica. Its range embraces the whole of 

 tropical Africa from Liberia to Damaraland and east- 

 ward to the East Coast. It is a creature of sterile, 

 sandy places. When surprised, it makes no attempt to 

 get away, flattening against the sand, making short 

 jabs at the intruder and blowing noisily. The nostrils 

 open on the top of the snout, while the eyes might be 

 said to gaze upward, provisions enabling the creature 

 to imbed itself in the sand with the exception of the 

 top of the head, yet be alert for passing objects. It is 

 a "looper" or "sidewinder," progressing by throwing 

 loops of the body forward in a lateral fashion, when it 

 moves off in an oblique direction to that in which tlie 

 head is pointing. 



Of all the venomous snakes ever studied by the author, 



