1889-90.] MORPHOLCGY AND PHYSIOLOGY OF THE CELL. 263 



development, although it may depend on the change in the food, or 

 habitat, which the increased development entails. 



2. They are present in all the cells of the actively secreting pancreas 

 of Dietnyctylns, as well as in that of an animal fasting for two months or 

 more. When two or more are present in a cell, they are, usually, but not 

 always, small. I have found them present in the cells apparently without 

 diminution in number at every indicated interval, after the injection of 

 pilocarpin. In corrosive sublimate preparations of the gland cells distended 

 with zymogen granules, these bodies are, in many cases, not seen. It one 

 relied wholly on corrosive sublimate as a hardening reagent, one might 

 conclude that this is a stage in which the nebenkerne are absent, having 

 been used up in the formation of zymogen, and such a conclusion has been 

 advanced by Ogata. That the bodies are not absent, but merely obscured 

 by the granules, is shown in preparations made with Flemming's Fluid 

 from a pancreas in the same condition. This reagent dissolves out the 

 zymogen in the centrally placed tubules, and, if allowed to act for twenty- 

 four hours, blackens the structures in question, thereby showing them to 

 be as numerous in this phase of cellular activity as in any other. I 

 have, however, found that they, as a rule, stain somewhat more readily 

 with eosin at certain intervals after injections of pilocarpin, and this 

 condition is concurrent with the filling up of the exhausted cell with 

 zymogen, and with a subsequent exhaustion of the same. The deeper 

 stain during the formation of zymogen is due to absorption of the latter 

 diffused from the nucleus, its seat of formation, while, in the other case, 

 the cells, having their energy exhausted, cannot destroy or disintegrate 

 the organisms, which absorb the cell juices and thereby attain a greater 

 readiness for eosin. I think this latter condition is in some way connected 

 with the vitality of the animal, for it is less apt to appear in vigorous 

 animals, and I found it best exemplified in sluggish ones, while in some 

 cases, again, it appeared in forty-five to fifty-five hours after the adminis- 

 tration of one dose of pilocarpin. 



3. They are not derived from the nucleus by constriction and partial 

 chromatolysis, as Platner describes, although other structures described 

 farther on, with which these have been confused, may be so derived. I 

 have examined series of sections made from the pancreas of over seventy 

 Diemyctyli, exhibiting all the phases of glandular activity and yet I 

 have never in a single instance seen the bodies in question, in any way, 

 derived from the nucleus, nor are they plasmosomata which have migrated 

 from the nucleus and have undergone a certain amount of extranuclear 

 development, a thesis which Ogata adopts and defends. I have found 

 extranuclear plasmosomata, and, as will be seen from the description 



