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R. R. BENSLEY 



separated from the duct system. The examination of prepara- 

 tions fixed in Zenker's fluid and stained by Mallory's aniline blue 

 method for connective tissue, shows that the apparent continuity 

 between islets and acini or ducts is real, and that no connective 

 tissue fibrils are interposed between the islet and the acini with 

 which it appears to be continuous. In the islets of this class it 

 is impossible to define a capsule, though such a structure may with 

 justice be ascribed to the islets of class 2. 



Fig. 9 Section through a small tubule near its origin from the pancreatic duct, 

 showing origin of islet cells from undifferentiated epithelium. In some of the islet 

 cells only a few granules are seen. Guinea pig; chrome sublimate, neutral gentian; 

 c, capillaries; i, islet cells. X 533. 



The islets of class four are those which have lost their connec- 

 tions with ducts. It is impossible to judge from my preparations 

 how frequently this separation occurs, for the pressure necessary 

 to flatten the preparation so as to spread the tissues apart may 

 have broken the connections. This has happened frequently, 

 for one can still see the torn duct going in the direction of the 



