THE INTESTINES. 
283 
supported by 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 through 
the pyloric orifices intc the intestines. The length of "the 
intestines in animals bears a proportion according to the 
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 other viscera. It inti¬ 
mately adheres by fine cellular tissue to the muscular coat 
underneath. It serves to strengthen the 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 
are confined in their proper situations. If the intestines 
were allowed to float loosely in the abdomen, they would 
