THE DIGESTIVE SYSTEM 



255 



depends upon their lunclional cundiLion (p. 277). They usually 

 appear clear and granular and take a light stain. 



The parietal cells (Fig. 157), are oval or polygonal in shape, and 



^^U 





lie here and there against the base- 

 ment membrane. The nucleus is 

 spherical, somewhat larger than that 

 of the chief cell, and is usually situ- 

 ated at the center of the cell. There 

 may be two nuclei. The protoplasm 

 is finely granular^ and in the fresh 

 unstained condition appears clearer 

 than that of the chief cells. The 

 parietal cells stain intensely with the 

 aniline dyes with the result that in 





Fig. 156. Fig. 157. 



FiG 156. — ^Vertical Section through the Mucous Membrane of the Fundus of the 

 Stomach. X85. (Kolliker.) Mg, Gastric pits; /?, neck; k, body; g, fundus of peptic 

 glands; h, chief cells; h, parietal cells; m, muscularis mucosae. 



Fig. 157. — Cross-sections at Various Levels of Peptic Glands of Stomach. X400. 

 (Kolliker.) M, Section through gastric pit near surface; M', section through gastric 

 pit near bottom; //, mouth of gland; k, neck; g, body near fundus; a, chief cells; b, 

 parietal cells. 



stained specimens the two kinds of cells are in marked contrast, the 

 parietal cells being much darker than the chief cells. Although lying 

 against the basement membrane and frequently pushing it out so as 

 to form little protuberances beyond the even line of the gland tubule. 



