CYTOLOGICAL STUDIES OF LANGERHANS's ISLETS 31 



of the cell-body. The striking changes are those of the intra- 

 nuclear network. The nucleolus or nucleoli, as well as nucleolar 

 corpuscles, increase in volume so that the network becomes more 

 pronounced; the nuclear membrane, in addition, increases in 

 thickness, stains more deeply than before, and is often thrown into 

 folds. In other words, the nucleus exhibits a marked nucleolar 

 hyperchromasy (Saguchi, '15). The process is not confined to 

 the nucleus; it extends at successive periods, to the cytoplasm 

 so that the latter stains more or less deeply with iron-hemo- 

 toxylin or acid fuchsin. 



The most striking change in the cytoplasm is that of the mito- 

 chondria. In my previous work I mentioned that the acinus 

 cell contains thick and coarse mitochondrial filaments. In the 

 first stage of transformation (fig. 8) there appear along the course 

 or at the ends of these filaments, which have meanwhile become 

 thickened and more or less shortened, spherical or oval enlarge- 

 ments in which one can distinguish very soon after their forma- 

 tion a clear inner part and a heavily staining cortical layer, due 

 perhaps to the production of liquid in the accumulated mass of 

 mitochondrial substance. This process of liquefaction extends over 

 the whole length of the thickened mitochondrial filaments, while 

 the heavily staining cortical layer disappears; at last there remain 

 only canaliculi or spaces filled with the clear liquid (figs. 9, 10). 



In preparations treated by the uranic nitrate-silver methods of 

 Cajal, one often sees acinus cells containing 'ong or short, brown 

 or black, spherical or oval, rod-, club-, or dumb-bell-shaped cor- 

 puscles which are scattered through the cytoplasm, often reach- 

 ing the distal end of the cell (fig. 24). Concerning the signifi- 

 cance of these corpuscles no definite conclusion could be drawn 

 from my observations since I could not follow out the process of 

 their formation. One thing, however, is certain — they have no 

 definite genetic connection with the Golgi apparatus, which 

 shows the same staining reaction, for there are found cells in 

 which these structures are visible, independent of the network 

 apparatus near the base of the cell. I am of the opinion that 

 the formation of these corpuscles and the liquefaction of mito- 

 chondrial filaments are one and the same process; the mitochon- 



THE AMERICAN JOUKNAL OF ANATOMY, VOL. 28, NO. 1 



