66 



STRUCTURE AND ECONOMY OF THE HORSE. 



openings, one communicating with the oesophagus, the other 

 Avith the small intestines. The former is called the cardiac 

 orifice, and is situated about tlie middle of the small curvature. 

 It has a sort of valve formed by the duplication of its mena- 

 branes, and is kept constantly closed, except when food is 

 passing. 



This cut represents the Stomach and Liver cut open, so as to show their internal 



surfaces. 



1, The CESophagus. 



2, The cardiac orifice of the stomach, 



so arranged as to prevent vomit- 

 ing. 



3 3, The white, cuticular, insensible 



portion of the stomach. 



4 4, The line separating each portion. 

 5, Tlie villous, or sensible, portion. 



6, The pyloric orifice, opening into 



the duodenum. 



7, The red mucous membrane of the 



duodenum. 

 8 9, Orifice of the duct leading from 



the liver. 

 10, Orifice of the duct leading from 

 the pancreas. 



The other orifice, called the pyloric, is situated at the right or 

 small end of the stomach, and is usually open, but has the power 

 of closing. Thus situated, these openings are not far distant 

 from each other, and in the usual position of the animal they 

 are situated superiorly. The oesophagus, just previous to its 

 entering the stomach, makes an acute angle, by which means, in 

 great measure, vomiting in the horse is almost entirely for- 

 bidden. The stomach is kept in its situation principally by the 

 oesophagus and the duodenum ; but it is also attached by means 

 of peritoneum to the spleen, liver, colon, and diaphragm. 



The stomach of the horse will usually contain about three 

 gallons. 



The intestines are usually distinguished into the small and 

 the large. They are more bulky and longer than in the human 

 subject, being nine times the length of the body in the horse, 



