182 



OEGANS OF DIGESTION. 



mass, rather than of elements having a cellular character ; the 

 wall of the gland is formed of a transparent structureless mem- 

 Fig. 184. br ? ne - Be ' 



sides these 

 granular cor- 

 puscles an al- 

 buminous 

 fluid exudes 

 fromthewalls 

 of the sto- 

 mach, and 

 mingles with 

 that yielded 

 by the gastric 

 glands ; the 

 gastric juice 

 appears to be 

 loaded with 

 corpuscles, 

 having a pe- 

 culiar acid 

 mixed with it, 

 secreted by 

 an appropri- 

 ate set or 

 glands, from 

 which it is 

 expressed by 

 the contrac- 

 tion of the muscular coat of the stomach, when excited into 

 action by the presence of food. T. W.] 



331. The result of this process is the reduction of the 

 food to a pulpy fluid called chyme, which varies in its nature 

 with the food. Hence the function of the stomach has been 

 named chymification. With this the function of digestion is 

 complete in many of the invertebrata, and chyme is circulated 

 throughout the body ; this is the case in polyps, acalephse, 

 some worms, and mollusca. In other animals, however, the 

 chyme thus formed is transferred to the intestine, by a pecu- 

 liar movement like that of a worm in creeping, which has 

 accordingly received the name of vermicular or peristaltic 

 motion. 



