VIPERINE GROUP. 
235 
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, carried it home; its true character being only 
discovered when it bit a dog.” 
Puff-Adder ^- n ^ r ^ ca the pl ace of Russell’s viper is taken by the dreaded 
puff-adder ( V. arietans), which occasionally attains a length of 6 feet. 
It is the only member of the genus in which the unusually small nostrils open 
THE PUFF-ADDER (£ liat. size). 
upwards 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 longitudinal rows, and forming three or four series 
between the eyes and the upper labials. The coloration and marking vary to a 
certain extent individually; but there is a great change in the brightness of the 
tints immediately after the changing of the skin. The puff-adder is spread over 
