182 MICROSCOPIC ANATOMY OF THE ORGAXS. 



two kinds of cells, the chief cells and the parietal cells (R. 

 Heidenhain). 



The chief cells, also called adelomorphous cells (Rollett), 

 form the largest part of the gland. These are round or 

 cubical, the form and size depending on their functional 

 activity. During a period of fasting and at the beginning of 

 digestion they are large, while after digestion has proceeded for 

 a certain length of time they become much smaller. In the 

 fresh condition they contain numerous highly refractive gran- 

 ules, which, as in other glands (pancreas, parotid, etc.), disap- 

 pear in the outer zone of the cell during secretion. These 

 granules are supposed by most authorities to consist of a sub- 

 stance, pepsinogen, which is converted into pepsin. 



The parietal cells (delomorphous), also known as oxyntic 

 cells, are larger and more conspicuous than the chief cells. 



FIG. 136. 



Parietal eel 



Tunica propri 



Chief cell- 

 Transverse sections of glands from the fundus of a mouse. X 300. 



They are not regularly arranged in the gland tubules, but are 

 scattered here and there in the rows of chief cells. In the neck 

 of the -gland they are usually very numerous, and may lie in 

 rows like the chief cells. They are generally only sparingly 

 present in the gland body. Here they are pressed out by the 

 chief cells against the membrana propria, so that they seem to 

 be at the periphery of the tubule. A cross-section of the 

 tubules gives an accurate idea of the relation of these cells to 

 one another (Fig. 136). The parietal cells are round or 



