THE HORSE AND ITS DISEASES. 85 



distention backward being prevented by the pressure of 

 the stomach upon the diaphragm ; hence, we see the 

 great impropriety of galloping horses after watering, to 

 warm it in their bellies, as it is foolishly termed, and 

 also how hurtful it is to ride hard immediately after a 

 horse has been full fed. 



The inner covering of the stomach is composed of two 

 portions, a cuticular, and a villous. 



This species of cuticular, covering rarely to one half 

 of the stomach, is peculiar to such animals as appear 

 destined to live on grain, as horses, asses, rats, and 

 mice ; and this forms a thii'd species of stomach between 

 the true membranous, one of graminivorious animals, 

 and the muscular of the carnivorous tribes. 



The villous or sensible portion, though it occupies 

 more of the length of the stomach, yet perhaps, in real 

 extent, extends over little more than half its surface ; 

 it unites with, or is connected to the cuticular coat. 

 Its external surface is firm, and appears as it were a 

 distinct portion, but is nothing more than the general 

 cullular membrane — here rather more dense, which has 

 given rise to the description of four tunics to the stomach. 

 The vessels of the stomach are three very considerable 

 branches — the two gastrics, and one fi'om the pancreatic, 

 which are ramified over its different portions, forming 

 two considerable arches, one over the small, the other 

 over the great extremities. The blood is returned by 

 similar veins into the vena porta. The nerves are deri- 

 ved from the par vagum, which are the eight pair that 

 arise from the brain, and passing out of the skull — are 

 continued on the outside of the carotids to gain the 

 oesophagus, and proceed with it, uniting with the inter- 

 costal to furnish some branches to the thoraic visore, and 

 are then spent upon the stomach. It is probable some 

 particular end is brought about by this peculiar origin 

 of the nerves of the stomach ; and it is more than prob- 

 able, that it is by this means that it proves so greatly 

 an organ of sympathy. 



