THE PANCREAS 



399 



N 

 A B 



FIG. 371. CELLS FROM PANCREAS OF NECTURUS. 



A, after rest, and filled with zymogen granules; B, after activity, showing the 

 presecretion (basal; ergastoplasmic) filaments, and the so-called nebenkern (N). 

 (After Mathews.) 



idea that either the basal filaments of Solglr or the mitochondria give 

 origin to secretory granules, by a process of segmentation. 



Pancreatic Islets. The lobules of the pancreas contain, in addi- 

 tion to the acini and ducts, certain larger and smaller spheroidal col- 

 lections of polyhedral ^cells which lie m the inter-acinar connective tissue, 

 the pancreatic islets (islands of Langerhans; intralobular or interalveolar 



FIG. 372. Two ADJACENT ACINI FROM THE GUINEA-PIG'S PANCREAS. 



/The one at the right shows an entering intercalary duct and two centro-acinal 

 cells. The acinar cells are filled proximally with a basophilous substance (basal 

 filaments), and contain distally numerous alveoli, the representatives of dissolved 

 zymogen granules. X 1200 (After Bensley, Am. Jour. Anat., 12, 3, 1911.) 



