THE TAXCREAS. — SPLEKX. — OMEXTUM. 319 



times, and in tlie quantities, wliicli tlie pui^poses of digestion require ; but 

 the horse has no gall-bladder, and, consequently, the bile flows into the 

 intestine as rapidly as it is separated from the blood. The reason of this 

 is plain. A small stomach was given to the horse in order that the food 

 might pass quickly out of it, and the diaphragm and the lungs might not 

 be iujuriously pressed upon, when we require his utmost speed ; and also 

 that we might use him with little danger compared with that which would 

 attach to other animals, even when his stomach is distended with food. 

 Then the stomach, so small, and so speedily emptied, must be oftener 

 replenished ; the horse must be oftener eating, and food oftener or almost 

 continuously passing out of his stomach. How admirably does this com- 

 port with the uninterrupted supply of bile ! 



THE PANCREAS. 



In the domestic animals which are used for food, this organ is called the 

 sioeet-hrcad. It lies between the stomach and the left kidney. It much 

 resembles in structure the salivary glands in the neighbourhood of the 

 mouth, and the fluid which it secretes resembles the saHva in its properties. 

 The pancreatic fluid is carried into the intestines by a duct which enters 

 at the same aperture with that from the hver. It contains a peculiar 

 substance named pancratine. Its use, whether to dilute the bile or the 

 chyme, or to assist in the separation of the chyme from the feculent matter, 

 has never been ascertained : it is, however, clearly employed in aiding the 

 process of digestion. 



THE SPLEEN. 

 This organ, often called the viclt, is a long, bluish -bro'\^Ti substance, broad 

 and thick at one end, and tapering at the other ; lying along the left side 

 of the stomach, and between it and the short ribs. It is of a spongy 

 nature, divided into numerous httle cells not unlike a honeycomb, and 

 over which thousands of minute vessels thickly spread. The particular use 

 of tliis oi^gan has never been clearly ascertained, for in some cruel experi- 

 ments it has been removed without apparent injury to digestion or any 

 other function. It is, however, useful, at least occasionally, or it would 

 not have been given to the animal. It is probably concerned in the reno- 

 vation of the blood, and in the preparation of it for the secretion of bile. 



THE OMENTUM, 



Or caivl, is a doubling of the peritoneum. It is supposed to have been 

 placed between the intestines and the walls of the belly in order to prevent 

 concussion and injury du.ring the rapid movement of the animal. That, how- 

 ever, cannot be its principal use in the horse, from whom the most rapid 

 movements are required ; for in him it is unusually short, extending only to 

 the pancreas and a small portion of the colon. Being, however, thus 

 short, the horse is exempt from a very troublesome and, occasionally, fatal 

 species of rupture, when a portion of the omentum penetrates through 

 some accidental opening in the covering of the belly. 



The structure of the urinary organs and the diseases to which they are 

 ex^iosed will be hereafter considered. 



CHOKING. 



Although choking is rare in the horse as compared with the bovine 

 tribe, it is attended with much greater danger in the former. It generally 

 arises from the impactment of some hard substance either in the larpix or 

 oesophagus, more frequently the latter. Horses that are voracious feeders 

 frequently swallow their food so rapidly that mastication is not half 



