STOMACH IN THE DOG. 175 



structure different from that observed in man, and which was 

 once believed to be peculiar to the gullet in ruminating animals. 

 A mucous membrane lines the gullet, which, in the contracted 

 state of the organ, is thrown into folds. 



Stomach: The stomach in the dog is somewhat larger pro- 

 portionally than in man. It is placed more lengthwise in the 

 animal. It is also thicker and stronger than the human stomach. 

 In the dog the rugae go lengthwise from the cardia to the 

 pylorus. The cardia or communication with the gullet is con- 

 stantly closed except when food is passing from the gullet into 

 the stomach, or in the act of vomiting, when the contents of 

 the stomach are rejected upwards. It is almost at the extreme 

 left of the stomach, which manifestly renders vomiting more 

 easy. The stomach has three coats the internal or mucous, 

 the middle or muscular, and the serous or external, derived, 

 like the corresponding serous coat in other mammals, from the 

 general shut sac of the abdominal peritoneum. The motions 

 imparted to the stomach by the muscular coat serve to move 

 the contents of the stomach along the secreting mucous mem- 

 brane, so that the digesting aliment is more effectively sub- 

 jected to the solvent power of the secretion namely, the gastric 

 juice. As the chyme is formed it is expelled by the pyloric 

 or lower orifice into the duodenum. 



Intestines. The intestines in the dog, as in other mammals, 

 are divided into the small intestines and the great intestines. 

 The small intestines, as in other such animals, have three 

 divisions the duodenum, the jejunum, and the ilium ; and 

 the great intestines consist of the caecum, the colon, and the 

 rectum. There is much less difference in dimension between 

 the small and the great intestines in the dog than in the horse. 

 The whole intestinal tube in the dog does not average more 

 than five times the length of the body, and the small intestines 

 average about seven times the length of the great. The 



