ioo INTRODUCTION 



lasts much longer in the large Boas and Pythons. 

 Thus, in the above-mentioned Anaconda it has been 

 observed to take from nine to thirty-eight days. 

 Even the hardest bones of birds are decomposed by 

 the gastric juices, but hairs, feathers, and horny pro- 

 ductions, are passed with the excrements, sometimes 

 forming regular balls. It is in most cases possible to 

 tell, from an inspection of the dried faeces, what a 

 snake has been feeding on, hairs, feathers, beaks, 

 claws, epidermal horny shields, bits of tooth-enamel, 

 being found mixed with the chalky matter which 

 represents the decomposed bones. As a rule there 

 is but one defecation after each meal, but there are 

 in addition more frequent renal dejections, consisting 

 chiefly of uric acid. 



In captivity snakes show themselves capricious in 

 the choice of food, one individual preferring mam- 

 mals, whilst another, of the same species, will 

 only take birds ; and many, although to all appear- 

 ances perfectly healthy, will persist in refusing all 

 food, and allow themselves to die of starvation — a 

 suicide which may require months, or even years, to 

 accomplish. A Rattle-snake in the menagerie of the 

 Jardin des Plantes in Paris has lived two years and two 

 months without taking any food, a Python sebcs nearly 

 two years and a half, a Boa madagascariensis four years 

 and a month. A Vipera aspis was kept for three 

 years without food and without losing its vicious 

 temper. Specimens thus fasting do not, as a rule, 



