788 DR. p. CHALMERS MITCHELL AND MR. R. I. POCOCK [Nov. 12, 



Poisonous Viperine Snakes. — Puff-adders, Ooppei-heads, and 

 species of Lachesis very often strike dead food when it is thrown 

 to them, or when it is dangled in front of them or otherwise 

 made to simulate life. They strike and let go their hold in a 

 moment, the strike and disengagement being equally rapid. 

 If the prey is very small they occasionally swallow it at once. 

 "When swallowing dead food that they have struck and released, 

 or, as frequently happened, that they had never attempted to 

 strike, they are not infrequently indifferent to the direction of the 

 hair, but begin to swallow from the anterior or posterior end of the 

 prev with equal readiness. Salivation appeai-ed to us to be much 

 more copious than in the case of the Pythons. 



It is possible that the rapid disengagement of the fangs after 

 striking may be a protective instinct by which the snake avoids 

 being bitten or clawed by its prey before the poison has taken 

 effect. 



Detailed Record. 



In all these cases the prey was killed before being offered to the 

 reptile. 



Reticulated Python {Python reticulatus), 

 (East Indies.) * 



a. A large specimen, judged to be 24 feet in length, deposited 

 in Aug. 1898. This Python was thin and lethargic in the early 

 part of the summer and could not be induced to feed until August. 

 But having once made a start, he continued to feed till November 

 while the warm weather lasted, and took in all six goats and six 

 ducks. He never showed keenness, however ; and was never seen 

 to seize his prey with the swift head-drive characteristic of speci- 

 mens c and d, even when it was made to move. He always 

 approached it slowly and took it in a leisurely and deliberate 

 manner, after searching for the head in the way described above. 

 Quite commonly he refused to touch it before nightfall. 



h. Of two large specimens deposited in April 1907, one did not 

 feed before being returned to the depositor in September. The 

 other refused all food through June and July but began to feed 

 in August. He rapidly picked up in condition and on October 

 25th took one duck, one rabbit, one guinea-pig, and two pigeons ; 

 and on November 1st swallowed a small goat. 



c. Presented in Oct. 1898. Always lively and vicious, this 

 snake fed with great regularity all through June, July, and 

 August, only refusing food on one or two occasions when sick for 

 shedding. Rabbits were usually given ; but he took a kid one 

 day, although not with eagerness. 



* Brackets indicate t]i.it the exact locality of the particular specimen is unknown. 



