42 PHYSIOLOGY AT THE FAKM. 



namely, the hepatic, the gastric, and splenic. The gastric 

 runs towards the small curvature of the stomach between the 

 layers of the lesser omentum, giving off branches which encircle 

 the stomach by passing before and behind that organ. The 

 splenic artery and the hepatic artery send additional branches, 

 which run along the great curvature of the stomach. 



The veins of the stomach do not immediately join the great 

 systemic venous trunk, but first contribute to form the portal 

 vein, by which, as before mentioned (p. 9), the venous blood 

 of all the organs termed by anatomists chylopoetic viscera, is 

 transmitted through the liver before it reaches the systemic 

 venous system. 



The lymphatics of the stomach are very numerous. Some 

 are placed beneath the peritoneal coat ; others between the mus- 

 cular and mucous coats. They take a retrograde course in the 

 direction of the several sets of arterial branches, which reach 

 the stomach, and finally terminate in the nearest lymphatic 

 and lacteal trunks. 



The nerves of the stomach are large : they consist of the 

 two terminal branches of the pneumo-gastric nerves of the 

 eighth pair of cranial nerves, together with offsets from the 

 solar plexus of the sympathetic system. 



Digestion in the Stomach of the Horse. Animal bodies 

 are produced, without the slightest exception, from the ele- 

 mentary substances existing in the mineral kingdom. It 

 was already mentioned (p. 1) that there are fifteen element- 

 ary substances that is, substances which chemists have not 

 yet been able to decompose known to exist as the component 

 parts of the bodies of ordinary mammals, like the horse, ox, 

 and sheep. It was also noticed above that the perfect health 

 of such an animal cannot be continued, unless every one of 

 those fifteen elementary substances be supplied in the food, as 

 fast as it is lost or thrown out by excretion from the animal 



