THE GASTRIC JUICE. 49 



aspect of the interior of the stomach, Dr. Beaumont, who had an opportuni- 

 ty of examining it in the case of Alexis St. Martin, describes Aspect of inte- 

 it as of a light pink color, its velvety surface Ibeing coated nor of stomach. 

 over with mucus. On the introduction of food or any irritant, lucid 

 points protrude from the mucous coat ; these are the mouths of the folli- 

 cles from which the juice exudes. When in activity, the temperature 

 of the interior of the organ is about 100 Fahr. 



The gastric juice is a viscid fluid, with an acid reaction and faint odor. 

 After filtration through paper it is clear and transparent, and The gastric 

 possesses all its physiological qualities. The impurities thus J uice - 

 separated from it are merely old undigested residues, on which, in no re- 

 spect, its qualities depend. It does not become turbid at 212, remains 

 long undecomposed, and retains its digestive power even after it has be- 

 come mouldy. It does not accumulate in the stomach while fasting, but 

 requires a stimulus for its ejection, and even then is produced in a limit- 

 ed quantity only. It is secreted by the follicles of the mucous membrane 

 of the stomach, which follicles may be described as cup-shaped cavities, 

 about the two hundredth of an inch in diameter, from the bottom of which 

 project two or more parallel tubes, the mouth of the cup open- i t i ssec retedby 

 ing into the stomach, and the tubes ending in a closed term- follicles, 

 ination in the tissue beneath. Toward the pylorus the cups become deep- 

 er, so as to assume the form of a cylinder, and the projecting tubes are 

 shorter. Between these follicles blood-vessels pass. They are ramifica- 

 tions from the cceliac axis, and discharge a double function. As the ar- 

 terial branches invest the roots of the tubes, they furnish nutrition for the 

 cells which are produced in crowds at that part of the arrangement ; but 

 when they have gained the interior of the mucous membrane, and are in 

 the ridges between the follicles, having assumed the character of veins, 

 they act as absorbents, conducting the material which is sufficiently di- 

 gested into the portal circulation. Agreeably to this, these vessels have 

 a larger diameter than capillaries generally. It seems, therefore, that the 

 function of the tube is the production of cells, which, originating from 

 germs at the bottom and sides of each tube, become perfected as they pass 

 forward, and soon after their extension burst or deliquesce, and as the 

 material they discharge does not possess the acid reaction, it is probably 

 the pepsin element of the gastric juice. 



Constitution of the Gastric Juice of the Dog. 



D 



