31 



through the channels of practical experience, and frequently we 

 have paid dearly for it. 



One of the most important factors to be taken into account in 

 the feeding and watering of horses is the anatomical arrangement 

 of the digestive organs. The relative size of the stomach of the 

 horse, as compared with that of the other domestic animals, is 

 small. When distended, it has a capacity of twenty-five or thirty 

 pints. In case normal digestion is taking place, it rarely contains 

 more than seventeen or eighteen pints. The arrangement of the 

 mucous membrane is peculiar, in that it is sharply divided into two 

 parts, the cuticular portion being continuous with the mucous lin- 

 ing of the oesophagus. The villous membrane lines the right half 

 of the stomach, extending to the pyloric opening ; the left portion 

 is preparatory in its function. The membrane of the right half 

 contains the glands which secrete the digestive juices ; the right 

 half is the digestive portion. Stomach digestion in the horse goes 

 on very rapidly. The length of time required to digest a food 

 varies with its chemical composition, mechanical condition, bulk, 

 etc. As a rule, it may be stated that the more nitrogenous a food 

 the longer it remains in the stomach. It may happen that the 

 nitrogenous food may remain in the stomach but a short time, 

 being forced into the intestines by the ingestion of large quantities 

 of non-nitrogenous material ; for example, corn, oats or other ni- 

 trogenous grains ordinarily remain in the stomach longer than hay, 

 but by feeding grains first and hay in large quantities afterwards 

 the grains may be forced into the intestines undigested. 



Colin's and Smith's experiments with reference to stomach di- 

 gestion of hay and oats are interesting and instructive. They 

 found that when small amounts of food are given after fasting 

 they pass directly to the right side of the stomach, becoming in a 

 short time thoroughly mixed with and acted upon by the gastric 

 secretions. As soon after feeding begins as the stomach attains a 

 certain size, the ingesta passes out into the intestines as rapidly as 

 it comes in through the oesophagus. This occurs regardless of the 

 composition or condition of the food mass. As soon as the animal 

 stops eating, the food passes into the intestines more slowly ; it 

 continues to pass out, however, until the stomach* becomes con- 

 siderably reduced in size, then the stomach empties itself very 

 slowly. It would seem that nature intended that a portion of the 

 ingesta should remain in the stomach to act as ballast. It requires 

 from twelve to fifteen hours for the stomach to completely empty 

 itself. It has been found by experiment upon horses that the in- 

 gesta arranges itself in layers in the stomach in the order in which 

 it is taken in, that arriving first going into the pyloric portion of 



