STRUCTURE OF THE PANCREAS. 



231 



FIG. 127. Pancreas of dog during second stage of digestion ; alcohol, carmine 



(after Heidenhain). 



In the connective tissue are groups or islets of epithelium-like 

 cells (Figs. 129, 130), which are supposed to produce the internal 

 secretion of the pancreas (p. 239). 



Outer zone of 

 a secretory 

 cell. 



Connective- 

 tissue. 



Larger gland- 

 duct. 



Intermediate 

 tubule. 



Inner granu- 

 lar zone of 

 secretory 

 cells. 



FIG. 128. From section through human pancreas ; X 450 (sublimate) (Bohm and 



David off). 



