DIGESTION. 47 



thus rendering it soluble. The constitution of the saliva 

 is also slightly alkaline, and more so while the animal is 

 masticating its food. A horse or an ox is supposed to dis- 

 charge about two quarts of saliva in a half hour whilst 

 masticating its food. This is sufficient to insalivate a small 

 ration of hay, or what the animal could masticate in that 

 time. The mere sight of food excites the flow of saliva, 

 causing the mouth to " water," and the harder and drier 

 the food the more the saliva will flow during mastication. 

 It is also found that after swallowing even sloppy food saliva 

 will continue to flow into the mouth. The saliva must be 

 considered a most important factor in the process of diges^ 

 tion. And for this reason the food of ruminants is best 

 given in such form as to insure its remastication. This is 

 accomplished by mixing finely-ground food with fibrous 

 fodder, causing both to be raised in the cud and remasti- 

 cated. The proper preparation of dry fodder by chopping 

 in a cutter, as an aid to mastication and digestion, will be 

 considered in a future chapter. 



STOMACH OF SOLIPEDS. 



The stomach of the horse (fig. 1) is a membranous sac 

 situated on the left side of the abdominal cavity, close be- 

 hind the diaphragm ; has the spleen attached to its left 

 extremity, and its lower part covered with the caul. It has 

 been compared in shape to the Scotch bag-pipes. It is so 

 situated that every contraction of the diaphragm, or inspir- 

 ation of air, displaces or drives it back, and the fuller the 

 stomach, the greater the labor of the diaphragm under 

 quick motion and frequent breathing, hence a full meal or 

 large draft of water should never be given just before great 

 exertion or rapid movement. The stomach of an average 

 sized horse holds only about three gallons. It has four 

 coats. The outside coat lines the cavity of the belly, and 

 is the common covering of all the intestines, and this coat 

 secretes a fluid which prevents all friction between it and 



