1907.] ON SERPENTS IN CAPTIVITY. 787 



of the Python group make a mistake in its selection of the head 

 and snout to begin on, and it is plain that the lie of hairs, or 

 feathers, the position of horns and the general shape of the body 

 of vertebrates, justify the snake in its choice. Occasionally in the 

 process of swallowing, a coil of the snake appears to push against 

 the posterior end of the prey, but this appears to be simply a 

 means of holding the prey steadily. The mechanical process is 

 one in which the snake pushes itself outside the carcase ; it gives 

 a huge gulp and fixes its teeth as far back over the body as is 

 possible, and then slowly, in big wrinkles, pushes a portion of its 

 mouth and gullet forwards ; then with another gulp gets its teeth 

 fixed still a little further on to the prey and repeats the forward 

 bringing up of the body, the general appearance of the motion 

 being similar to that of the progression of an earthworm. 

 Frequently, when the prey is large, the process of ingestion is 

 not straightforward s, the jaws being moved first to one side and 

 then to the other, alternately. Whilst swallowing is taking place 

 there is a certain amount of salivation, but the discharge is not 

 so copious as in poisonous snakes, and no saliva is shed on the 

 prey before the swallowing begins. A carcase wetted all over is 

 one that has been swallowed and afterwards disgorged. 



So far as the quantity of food taken by Pythons in the course 

 of the year is concerned, our experience differs considerably from 

 that of Mr. H. IST. Ridley, who, writing of the specimens in the 

 Botanical Gardens, Singapore *, says : — " Small-sized Pythons 

 usually feed once a month. The large ones over 20 feet long usually 

 once in from six to nine months. One which was about 22 feet 

 long, not long after it was brought in, passed the remains of a deer. 

 It fed again some time later on three chickens, and remained 

 without food for six months, when it passed the remains of the 

 fowls and then ate a good-sized pariah dog, which lasted it for 

 nine months." 



Non-poisonous Colubrine Snakes. — Such snakes, e.g. Boodon 

 li7ieatus, Spilotes corais, behave very much like pythons in 

 feeding. They seize the prey with a straightforward dart of 

 the head and then, if it is of large size or moving, either lie upon 

 it or partially twist round it to hold it steady. They then select 

 the anterior end and begin to swallow it. If, however, the prey 

 is of small size and easily swallowed, they take it straight away in 

 the fashion of Cobras and Viperine snakes. 



Poiso7ious Colubrine, Snakes.- — Our snakes in this category 

 (Cobras) very seldom strike at dead food that is thrown to them. 

 When the door of the cage is opened, they fix their attention on 

 the keeper, and, if lively, stand up with the hood raised, watching 

 him. They take dead food readily, swallowing it in the fashion 

 of Viperine snakes, never being seen to lie partially over it or to 

 coil round it as is done by non-poisonous Colubrines occasionally, 

 and Pythons habitually. 



* Journ. Straits Branch K. A. Soc. no. 46, p. 189 (1906). 



