184 EQUINE PHYSIOLOGY. 



by the movement of its circular and longitudinal fibres forces it 

 through the cardiac orifice of the stomach into that viscus. 



The first stage is voluntary, the others involuntary. 



The horse can make from 65 to 90 motions of deglutition per 

 minute for fluids. 



GASTRIC DIGESTION. 



From the difficulty or impossibility of making a gastric fistula 

 in the horse, the amount and composition of the gastric juice is 

 hard to estimate. Its specific gravity is about 1010, its reaction 

 acid and its composition is as follows 



( Water ) 



Fluids,-! Hydrochloric acid > 982.80 



(Lactic acid j 



Solids 17.20 



The solids are 



Pepsin, 



Milk-curdling ferment, 



Chlorides, 



Phosphates, 



Iron. 



The amount of acids varies from 0.084 per cent, to 0.2 per cent. 



The juice from the fundus of the stomach contains more fer- 

 ment, more acid and more mucus than that from the pylorus. 

 Action of Gastric Juice. 



The gastric juice changes starch into sugar, not of itself, but by 

 the saliva, which still continues its action, converts vegetable 

 albumin into peptones, and digests cellulose by fermentation to 

 some extent. In feeding the horse the food should be taken in 

 the following order: first water, second hay, third oats, as the water 

 if given last would wash the food into the intestine before it was 

 acted upon by the gastric juice, while if hay was given after oats, 

 it would carry them along with it, as it is principally digested in the 

 intestines, the oats being acted upon by the stomach for the most 

 part. The stomach is never completely empty, as some food 

 remains after 24 hours. 



