DIGESTION. 



185 



occupied by them, the outer border being clear and hyaline in appear- 

 ance. The parietal cells during rest are large and finely granular, 

 but after secretion they are smaller in size though still granular. 

 (See Fig. 76, A and B.) 



,/The cells of the pyloric glands, though containing granules, dp not 

 show any marked difference between the resting and active condition. 

 According to some observers, they contain pepsinogen; according to 

 others, mucin. The epithelial cells lining the ducts of the pylorus 

 and fundus glands, if not identical with the epithelial cells on the sur- 

 face of the mucous membrane, pass by transitional forms into them. 

 Among these cells are found many goblet cells which secrete a portion 



b- 



FIG. 76. SECTIONS or DEEP ENDS OF FUNDUS GLANDS OF THE CAT IN DIFFERENT 

 SECRETIVE PHASES. X 1000. (Bensley.} A. From a fasting stomach. The 

 chief cells are filled with large zymogen granules; nuclei near the outer ends of 

 cells. Gentian-violet preparation, b b b. Border cells. B. Six hours after an 

 abundant meal of raw flesh. The chief cells exhibit two zones, the inner occupied 

 by large zymogen granules, the outer by a deeply staining, obscurely fibrillar 

 element, prozymogen; the nuclei lie at the junction of the two zones, b b b. Border 

 cells, pr. Prozymogen. c. Mucin-secreting cell, similar to those found in the 

 neck of the gland. Gentian-violet preparation. 



of the mucus found in the stomach and gastric juice. In the period 

 of rest the protoplasm of the epithelial cells absorbs and assimilates 

 from the surrounding lymph-spaces material which eventually makes 

 its reappearance as a product of metabolism in the form of granules 

 and hydrochloric acid. W4th the onset of digestive activity there is a 

 dilatation of the blood-vessels, an increase in the blood-supply, a 

 stimulation through the nerve-supply of the cells, and an output of a 

 fluid to which the name gastric juice is given. 



Influence of the Nervous System. The secretion of gastric 

 juice is largely ajejj&x act and under the control and influence of the 



