GASTRIC DIGESTION. 365 



The gastric juice of the hog contains the same ferments as are found 

 in the secretion of other mammals ; it dissolves albuminates and con- 

 verts them into peptone, parapeptone, and syntonin, and coagulates 

 milk, and, to a slight degree, as in the case of other mammals, splits up 

 fats into glycerin and fatty acids. 



The secretion obtained from different portions of the stomach differs ; 

 that obtained from the greater curvature contains more mucin, more 

 acid, and more ferment than that from the other portions, while the 

 secretion from the cesophageal portion is free from ferment. 



In the secretion from the greater curvature, as obtained by the 

 making of extracts with common salt, the degree of acidity varies from 

 0.03 to 0.07 per cent. 



The portion of the stomach supplied with the associate cells con- 

 tains all the ferments in the greatest quantity. Small amounts are found 

 in the pyloric region, and a still smaller amount in the cardiac diver- 

 ticulum. 



These ferments in the hog are with difficulty extracted with glycerin, 

 but are readily removed by means of dilute hydrochloric acid and salt 

 solutions. 



Ellenberger and Hofmeister further claim that there is a diastatic 

 ferment in the mucous membrane of the hog's stomach, and they have 

 proved by carefully controlled experiments that the conversion of starch 

 into sugar by means of artificial gastric juice from the hog is actually 

 due to the presence of the ferment. It does not, however, seem clear 

 as to whether this ferment is actually produced in the gastric mucous 

 membrane, or whether it enters that membrane by imbibition from saliva 

 which has been swallowed. The gastric juice of the fundus of the stom- 

 ach of the greater curvature produces coagulation of milk, both in 

 alkaline and in neutral conditions ; this power is not possessed by the 

 mucous membrane of the cardiac sac, and only to a slight degree by the 

 pyloric portion. No lactic acid ferment exists in the hog's gastric juice. 



The progress of gastric digestion in the hog has been carefully 

 studied by Ellenberger and Hofmeister, by administering definite amounts 

 of specific foods to hogs in whom the stomach had been emptied by 

 fasting and cleansed by copious administration of water. The animals 

 were then killed, at specific intervals after the administration of the 

 food, and the gastric and intestinal contents subjected to a chemical 

 examination. These authors' experiments were restricted to the cereals. 

 The largest number of experiments were made with oats, given dry, so 

 as to produce the greatest quantity of saliva. In other instances the 

 food was given moist, so as to reduce the secretion of saliva to a min- 

 imum. To those who received the dry food water was always given to 

 drink. The animals on whom these experiments were made were for a 



