THE VIPERS 2597 



deep as well as poisoned wounds. When disturbed, its loud hissing is calculated to 

 warn those who approach it, and it does not appear to cause many human deaths, 

 although it may be that its misdeeds are sometimes ascribed to the cobra. This 

 viper is said to frequently kill cattle while grazing, by biting them about the nose 

 or mouth. In proof of its sluggish nature, there is a well-authenticated tale of a 

 young person having picked one up, and, mistaking it for an innocent snake, car- 

 ried it home, its true character being only discovered when it bit a dog." 



RUSSELL'S VIPER. 

 (One-half natural size.) 



In Africa the place of Russell's viper is taken by the dreaded puff 

 Puff Adder ,, ., ,, 



adder ( v. artetans), which occasionally attains a length of six feet. 



It is the only member of the genus in which the unusually small nostrils open 

 upward near the extremity of the muzzle; and it is further distinguished by having 

 a supranasal shield, covered, like the region of the brow, with upright horny scales 

 or spines. In appearance most hideous and repulsive, this snake has the large and 

 flattened head triangular in shape, very broad and blunt at the muzzle, and sharply 

 defined from the body, the latter being thick and almost triangular in section. 

 Both head and body are covered with keeled overlapping scales, differing from one 

 another only in size, and arranged on the body in from thirty-one to thirty-three 



