DIGESTION OF POOD. 359 



that food is found in the stomach twelve hours after feeding ; 

 in the caecum after twenty-four hours, with a residue in the 

 jejunum ; after forty-eight hours, in the ventral colon, with re- 

 mains in the caecum; after seventy-two hours, in the dorsal 

 colon ; and after ninety hours in the dorsal colon and rectum. 



The caecum appears to digest large quantities of cellulose, 

 which does not seem to be affected by either the saliva, gastric, 

 or pancreatic juices. The process is ill understood. In her- 

 bivora the large intestine takes some very important part — in 

 digestion and absorption — and we would again remind the stu- 

 dent that the latter term has been used in a very vague if not 

 unwarrantable sense. It is important for the practitioner to 

 bear in mind that nutrient enemata can be utilized for the gen- 

 eral good of the economy when passed into either the large or 

 small intestine. 



During the suckling period digestion in all the various 

 groups of animals is probably closely analogous. At this time, 

 in ruminants, the first three divisions of the stomach are but 

 slightly developed. 



Pathological.— In subjects of a highly neurotic temperament 

 and unstable nervous system it sometimes happens that im- 

 mense quantities of gas are belched from an empty stomach or 

 distend the intestines. 



It is known that the oxygen swallowed is absorbed into the 

 blood, and the carbonic anhydride found in the stomach de- 

 rived from, that fluid. 



It will thus be seen that the alimentary tract has not lost its 

 respiratory functions even in man, and that these may in cer- 

 tain instances be inordinately developed (reversion). 



special' considerations. 



It is a matter well recognized by those of much experience 

 in breeding and keeping animals with restricted freedom and 

 under other conditions differing widely from the natural ones 

 — i. e., those under which the animals exist in a wild state — that 

 the nature of the food must vary from that which the untamed 

 ancestors of our domestic animals used. Food may often with 

 advantage be cooked for the tame and confined animal. The 

 digestive and the assimilative powers have varied with other 

 changes in the organism brought about by the new surround- 

 ings. So much is this the case, that it is necessary to resort tO' 



