268 TRANSACTIONS OF THE CANADIAN INSTITUTE. [YOL. I. 



Staining reaction, or persist for a time in a cavity of the cell protoplasm 

 and gradually loose their eosinophilous character. Forms of the latter 

 are rare but they can be distinguished from the cytolyscd products of 

 other cells by the fact that they are more or less eosinophilous, and by 

 the fact further, that one only is to be found in a cell, while similar bodies, 

 protoplasmic or otherwise, are absent from the adjoining cells. For the 

 purposes of the diagnosis of course serial sections are necessary. But 

 with these aids even, the process of determining whether a slightly 

 eosinophilous, extranuclear mass is a plasmosoma derived from the 

 nucleus is a difficult one. The disintegration into zymogen-like gran- 

 ules is easily distinguishable on account of the fact that the resulting gran- 

 ules are collected at one spot in the cell (not near the border) and from 

 their resisting the action of acetic acid. It is possible, on the other hand, 

 that a plasmosoma may neither disintegrate into zymogen-like granules, 

 nor persist with the gradual loss of the eosinophilous character in the 

 cell protoplasm. I observed in the pancreas removed from an animal 

 one and a half hours after the injection of pilocarpin, the ductlets filled 

 with zymogen in a granular condition and containing here and there a 

 large plasmosoma-like mass. In this case no intra-cellular plasmoso- 

 mata were observed, although zymogen was still present in the cells. I 

 think this phenomenon indicates that the pancreatic cell can, under such a 

 strong stimulus as pilocarpin furnishes, throw out of itself all material 

 not part of its own mechanical structure, and that the extranuclear plas- 

 mosomata may, in some cases, be disposed of in this way. 



That Ogata made the mistake he did in assuming that the extra- 

 nuclear plasmosomata become converted into nebenkerne and the latter 

 again into zymogen granules is very natural in view of what is described 

 above. The passage of plasmosomata from the nucleus to the cell, the 

 mingling of zymogen granules, either with the substance of the plas- 

 modium-like mass or with the fibrillae of the degenerated parasite and 

 the occurrence of protoplasmic masses loaded with eosinophilous gran- 

 ules are demonstrable facts which Ogata seems to have observed, and he 

 built up from these the theory outlined, a feat and a mistake which any 

 cytologist, who had paid as careful attention to the subject as Ogata did, 

 might have committed at that time. What was less excusable was the 

 construction of a theory of cell rejuvenescence, for although chromatolysis 

 was then unknown, or at least undescribed, and, therefore, the occurrence 

 in pancreatic cells of protoplasmic masses possessing chromatin unex- 

 plained, yet the knowledge concerning the indirect process of cell division 

 had then made a great advance and it was hardly necessary to postulate 

 the existence of another process. All things considered, however, Ogata's 



