DEFINITIONS AND TECHNICAL CONSIDERATIONS. 355 



Foods after being partly masticated, pass into the gullet and fall into the 

 paunch; here they remain for a reasonable time, and soften in contact with saliva 

 swallowed; those portions that are dissolved pass through into the second stom- 

 ach (recticnlum), then into a third and fourth stomach (manifolds and rennet). 

 The coarser portions that have not been sufficiently masticated remain in the 

 recticulum where they collect into a boll shape, when by special contraction 

 of the esophagean canal they return into the mouth and are again masticated 

 and mixed with saliva; when this operation is completed, this food passes 

 again through the esophagus into the third stomach or manifolds; by a 

 special arrangement of muscles it cannot again return to the mouth; from the 

 manifolds it reaches the fourth stomach (rennet). In perfectly matured ani- 

 mals the liquids all fall into the paunch where they remain but a short time. 

 Before a calf is weaned, the food passes into the rennet without undergoing the 

 preliminary stages that occur later; in fact the first three stomachs remain 

 during this early stage in an almost embryonic condition. 



This process continues until the paunch is almost entirely empty. Between 

 meals the emptying does not seem to be ever complete, as is made evident by 

 the fact that in the excrement of cows one finds a mixture of the ration being 

 fed and the one previously used. As pointed out elsewhere in this writing. 

 four or five days frequently elapse before any fodder is completely eliminated 

 from the system. 



Colin cites an example of a cow having fasted for two days and still having 

 over 140 Ibs. of dry fodder in the several compartments of its stomach. From 

 the time the bolus enters the stomach, it is kept in constant motion, being 

 more and more salivated with a fluid known as gastric juice. The total 

 volume of this fluid secreted during twenty -four hours is enormous, and 

 some authorities assert that it may reach one-fourth of the weight of the 

 bodv. It contains water in considerable proportion, also special ferments, 

 chlorids of sodium, potassium, calcium, and ammonia, also hydrochloric 

 acid, ferric and magnesium phosphate. The principal ferment is pepsin, 

 which depends upon a diluted acid for its action upon foods. The main func- 

 tion of gastric juices is that of converting albuminoids into peptones. 



After leaving the fourth stomach, the food passes into the small intestine, 

 where it comes in contact with very important secretions, such as bile and 

 pancreatic juice. The bile is green in color, gives an alkaline or neutral re- 

 action and is secreted by the liver. Its composition varies with the animal; 

 beside water and solids, it contains certain salts lecithin and cholesterin, fats, 

 mucin and coloring substances, also inorganic salts. An ox, according to 

 Colin, will throw out 5.7 Ibs. of bile per diem, while a horse secretes 13 Ibs.; 

 there is a continued flow during the passage of the food through the intestines. 

 The principal function of .bile is that of aiding in the absorption of fats: some 

 of the fat is transformed into glycerin and fatty acids. There follows a soap 

 formation due to their combination with the alkalies of the bile; this soap 

 helps the passage through the membranes of the intestines which assists in 

 assimilation. Through the intervention of bile, food does not decompose 

 during its passage through the intestines. There is another fluid also of very 



