142 



THE ESSENTIALS OF HISTOLOGY 



FlG. 174. A CARDIAC GLAND OF 

 SIMPLE FORM, FROM THE BAT's 



STOMACH. (Osmic acid prepara- 

 tion.) 



c, columnar epithelium of the surface ; 

 w, neck of the gland with central 

 and parietal cells ; /, base or fundus, 

 occupied only by principal or cen- 

 tral cells, which exhibit the granules 

 accumulated towards the lumen of 

 the gland. 



Fio. 173. A CARDIAC GLAND FROM THE DOG'S STOMACH. (Highly magnified.) 



d, duct or mouth of the gland ; 6, base or fundus of one of its tubules. On the right the base 

 of a tubule more highly magnified ; c, central cell ; p, parietal cell. 



