1912] Ditmars: Feeding Habits of Serpents 213 



when in their native environment, feed often upon the Indo-Malayan 

 wild swine. Examination of the excreta in sixty per cent, of a series 

 of about forty specimens investigated showed Hberal traces of the 

 bristles of Sus cristatus, and in numerous cases the horny coverings 

 of the feet. From several crates enclosing snakes of a length slightly 

 over twenty feet, were taken hoof coverings that were estimated to 

 have been those of wild hogs of at least seventy-five pounds weight. 

 Many captive specimens of this great snake refuse all other food but 

 swine, and examples twenty feet in length, swallow a fifty-pound pig 

 without difficulty. An occasional specimen will refuse all other food 

 but fowl. A sixteen-foot snake of this species, would take at a meal, 

 two eight-pound roosters. These big snakes do best if fed at inter- 

 vals of ten to twelve days. At intervals like this they feed regularly 

 for five or six months when there is an inclination to fast, this condi- 

 tion being stubbornly continued for three or four months. This 

 fast is evidently an instinctive trait that relates to seasonal condi- 

 tions in the natural environment. Most tropical snakes evince like 

 habits and the writer has observed that those which are voracious 

 enought to feed steadily throughout the year accumulate excess fats, 

 which so derange the important organs as to cause such reptiles' 

 deaths. It is only during the past three years that we have been 

 making regular schedules of the feeding of our more valuable reptiles, 

 and subjecting them, if they do not seem so inclined, to an annual 

 fast of several months duration. This process has quite reversed 

 our former records of the longevity of a number of captives repre- 

 senting tropical species. The writer is convinced that the impossi- 

 bility of keeping alive the big tropical vipers for more than a year's 

 time has resulted from feeding during a period when the animal 

 has secreted fatty sustenance to carry it past a period of hibernation 

 or sestivation, as the case may be. In support of this view he cites the 

 results of various post-mortems of apparently over-nourished reptiles, 

 in which an undue fatty condition has brought about marked changes 

 in the liver and attendant organs. This annual fasting period par- 

 ticularly appeals to the boas and pythons, which are of peculiarly 

 delicate organization that responds quickly to changes of temperature 

 and undoubtedly affects the feeding habits of these reptiles during the 

 well-defined seasons in the tropics. It should here be understood 

 that the tendency among all reptiles to secrete fatty nourishment to 

 be utilized in periods of prolonged fast, is by far the most pronounced 

 among the snakes. Among notes at hand, the writer is able to quote 



