GLANDULAR CELLS OF THE FROG'S PANCREAS 387 



changes, there is some difference of opinion. Some investi- 

 gators (Mouret, '95, '05; Galeotti, '95) believe to have found 

 zymogen granules in the lumen of alveoli and ducts, and con- 

 clude from this that the dissolution of at least a part of them is 

 accomplished outside the cell-body. The opinion of Steinhaus 

 ('90), Carlier ('96), Gamier ('00), and others is adverse to this; 

 they maintaining that the granules are dissolved by the time 

 of elimination; while Miiller ('96, '98), and Babkin, Rubaschkin 

 and Ssawitsch ('09) claim that the granules liquefy within 

 the cytoplasm, forming the so-called 'secretion vacuoles'. 

 Altmann (94), on the other hand, considers that the lique- 

 faction of zymogen granules takes place either within or outside 

 the cell-body, according to the kinds of glands. 



So far as can be seen from my preparations, there is no indica- 

 tion of the extrusion of granules as such; it seems, rather, that 

 they are eliminated after undergoing certain changes, but 

 without having formed vacuoles with liquid. In preparations 

 treated according to Marchi and stained with iron-haematoxylin, 

 in which the zymogen granules remain unstained, so that the 

 upper half of the cell-body exhibits a reticular appearance, 

 there can be discerned in close proximity to the lumen some 

 granules or masses, which are irregular in shape and stained a 

 grayish color, and which show a marked tendency to fuse 

 together (fig. 84) ; they can never be found elsewhere. While 

 in many preparations the contents of the lumen appear clear 

 and homogeneous, in the Marchi preparation there can often be 

 seen irregularly shaped masses, the staining reaction of which 

 agrees with that of the masses present at the free end of the cell. 

 Under favorable conditions, even the continuity of the two 

 with each other can be discerned. From these observations, the 

 inference would appear justifiable that zymogen granules, after 

 having reached the distal end, undergo changes in physical and 

 chemical properties and form by fusion the grayish staining 

 masses above mentioned. These pass out of the cell through 

 the pores into the lumen, a mode of secretion, which is in full 

 accord with that found by me ('15) in the dorsal glandular 

 cells of Hynobius larvae. 



