292 DIGESTION. 



the small intestine. This completes the distinction between 

 the two portions of the stomach, the cardiac division only, 

 as we have already seen, possessing a mucous membrane 

 capable of secreting the true solvent gastric juice. 



"The revolutions of the alimentary mass, thus accom- 

 plished, take place slowly, by gentle and persistent contrac- 

 tions of the muscular coat ; the food occupying from one to 

 three minutes in its passage entirely around the stomach. 

 Every time that a revolution is accomplished, the contents 

 of the stomach are somewhat diminished in quantity ; 1 prob- 

 ably, in a slight degree, from absorption of digested matter 

 by the stomach itself, but chiefly by the gradual passage of 

 the softened and disintegrated mass into the small intestine. 

 This process continues until the stomach is emptied, oc- 

 cupying a period of from two to four hours ; after which, the 

 movements of the stomach cease until food is again in- 

 troduced. 



Regurgitation, Vomiting, and Eructation. 



Rumination and Regurgitation. Regurgitation of part 

 of the contents of the stomach, in the human subject, though 

 of frequent occurrence, particularly in early life, is not strictly 

 a physiological act ; and is always due either to overloading 

 of the stomach or some pathological condition. But in some 

 of the inferior animals this is habitual ; a certain class, called 

 ruminants, regularly passing the food, after the first deglu- 

 tition, in small quantities from the paunch into the mouth, 

 where it undergoes a second mastication, and is only then 

 permitted to pass to the secreting stomach and the rest of 

 the alimentary canal. Animals of this class, examples of 

 which are the ox, sheep, goat, and the camel and the deer 

 tribe, are invariably herbivorous, and take into the stomach 

 a large bulk of matter from which is elaborated a compara- 

 tively small quantity of nutriment. During the period when 

 they are nourished by milk, rumination does not take place. 



1 BEAUMONT, op. cit., p. 113. 



