THE IIVTESTINES. 283 



supported bj the abdominal muscles, and one or more of 

 them are found in every portion of the cavity of the belly, 

 and collectively fill nearly its whole space. 



The length of the intestines of the horse of full dimen- 

 sions is ninety feet, or between eight and nine times the 

 length of his body. Those of man are about sixty feet 

 long, or six times the length of the body. 



The food having been partially digested in the stomach, 

 and converted into a substance called chyme, passes throuo-h 

 the pyloric orifices into the intestines. The length of the 

 intestines in animals bears a proportion according to tlie 

 nature of the food. The nutritive portion of vegetables is 

 extracted with much more difficulty than with animal 

 substances, and hence the necessity of the alimentary canal 

 being much longer and more complicated in the horse and 

 other animals which feed upon vegetables. This viscera 

 is divided into the small and large intestines, from the 

 latter exceeding in volume the former. Each of these is 

 subdivided into three parts, all of which are composed of 

 three coats ; the first, or external one, is called the peri- 

 toneal ; the second, or middle, the muscular ; and the 

 third, or internal, the villous or mucous coat. 



The peritoneal coat is a covering continued from the 

 peritoneum itself, which includes the mesentric vessels and 

 nerves in its course to the intestines, and connects them tc 

 the spine, to one another, and to otlier viscera. It inti- 

 mately adt eres by fine cellular tissue to the muscular coat 

 underneatli. It serves to strengthen tlie tubes, and to 

 furnish a lubricating serous perspiration, which renders the 

 membrane smooth and moist, and serves to prevent all 

 friction and concussion By the aid of this coat the bowels 

 a.re confined in their proper situations. If the intestines 

 were allowed to float loosely in the abdomen, they would 



