34 



PHYSIOLOGY OF FARM ANIMALS 



[CH. 



alimentary canal at the posterior end of the oesophagiis. It acts 

 partly as a storehouse for food and so in man and many animals 

 obviates the necessity for nutriment being eaten at short 

 intervals, but it is also an important digestive organ in which 

 the food is acted upon by the gastric juice secreted by the glands 

 in its epithelial lining. The stomach is smallest and of least 

 functional importance in carnivorous animals such as the dog 

 which feeds on flesh to be converted into other flesh. In the dog 

 the stomach may be removed and the organ completely dispensed 

 with, without appearing to impair the digestive processes or the 



PYL. 



CARD. 



L.S 



CUT. 



BOU 



Fig. 21. Longitudinal section of stomach of horse (from 

 Smith, Messrs Bailliere, Tindall and Cox). Card. 

 oesophagus, Pyl. pylorus, Ij.S. left sac, i?.>S'. right 

 sac. (or pyloric portion), Gut. cardiac portion, Vil. 

 villous coat. Bolt, boundary between cardiac and 

 villous portions, Fiiiui. fundus or villous portion. 



health of the animal. In herbivorous animals in which the 

 processes of digestion are necessarily more complicated since 

 vegetable tissue has to be converted into animal tissue, we 

 frequently find a very complex stomach, but this is not necessarily 

 the case, for in the horse the stomach is small and simple, its 

 place being taken functionally to a great extent by the extremely 

 bulky large intestines which are reserved for the performance of 

 digestive processes that in the ox and sheep take place in the 

 rumen or first stomach. Thus maceration of vegetable fibre and 

 decomposition of cellulose is carried out in the horse to a large 

 extent in the colon and in the ox in the rumen. 



