234 DIGESTIVE SYSTEM. 



tine. Other aliments generally remain for some time in the 

 stomach, and the length of this period is determined by the 

 degree of difficulty which the stomach has in digesting them ; 

 those aliments which it cannot attack remaining in its cavity 

 as long as possible. 



We have to consider in the stomach : on the one hand, the 

 motor element peculiarity : and, on the other, the secretory or 

 epithelial peculiarity. 



I. The motory apparatus consists of a somewhat slight 

 fleshy tunic, which rarely contracts, and is incapable of any 

 great exertion, at least in man and in the mammalia. Those 

 peristaltic contractions which, by means of a sort of degluti- 

 tion, carry the contents of the stomach from the cardia to 

 the pylorus, and thence into the intestine, are extremely 

 gentle and slow ; since this kind of deglutition of bodies which 



Fig. 66. Muscular (oblique) fibres of the stomach (cravate de suisse) * 



are sharp, hard, and apparently injurious, has been known to 

 take place without being followed by any bad consequences. 

 These contractions are the result of a reflex action succeed- 

 ing the impression made upon the surface of the stomach by 

 the substances received, and appear thus to make a sort of 

 selection of those which are to remain a longer or shorter time 

 in the stomach. Thus fluids do not accumulate in this reser- 

 voir, even during a meal, and no very great difference is 



* The stomach appears turned over, and the muscular bands are shown by 

 the removal of the mucous coat. 1, Circular fibres of the oesophagus. 2, 3, Cir- 

 cular libres of the stomach. 5, Cravate de suiase. 



