118 A Manual of Veterinary Physiology. 



why it only digested 12 ozs. of oats in four hours. It will 

 be observed that the fifth horse in this series digested 

 nothing, even at the end of four hours ; I can only account 

 for this by the animal being in a strange place where the 

 feeding experiment was carried out, and being of a very 

 nervous disposition. 



Arrangement of Food in the Stomach. — An interesting 

 practical and physiological study is the effect of feeding 

 horses on different foods in succession. When hay is given 

 first and oats afterwards, the hay is found close to the 

 greater curvature and pylorus, and the oats in the lesser 

 curvature and cardia. No mixing has occurred ; both 

 aliments are perfectly distinct, and a sharp line of demarca- 

 tion exists between them (Fig. 9, I.). The presence of the 

 oats, however, has caused the hay to pass out more rapidly 

 than it would have done had it been given alone. Colin 

 observed that half the hay, but only one- fourth or one- 

 sixth of the oats, would, under these conditions, pass into 

 the intestine in two hours. During digestion a mixing 

 of these foods occurs at the pylorus, but nowhere else. 

 Ellenberger has shown that when hay and oats are given 

 in this order, a portion of the oats may pass out into the 

 bowel by the lesser curvature without entering either cardia 

 or fundus of the stomach (see Fig. 9, I.). No matter what 

 compression the contents have undergone as the result of 

 gastric contractions, the foods always remain distinct. 



When oats are given first, and followed up by hay, the 

 oats commence to pass out before the hay ; but the presence 

 of the hay causes the oats to pass more quickly into the 

 intestines (Fig. 9, II.). 



We may summarise these facts by saying that in a BUC 

 cession of foods the first taken passes out first; that does not 

 mean to say that the whole of it passes out before any por- 

 tion of the succeeding food enters the bowel, for we have 

 shown that after a time at the pylorus they mis and pass out 

 together; but the actual influence of giving a food first is 

 to cause it to pass out first. The practical deduction is that, 

 when foods are tnven in succession, the least albuminous 



