ACCOMPANYING THE SECRETION OF DIASTASE 431 
comparative standpoint is that, whereas in diastase-secreting cells 
the ferment is found directly by the nucleus, in the pancreatic cell 
the nucleus does not play an active rdle, but indirectly controls 
the zymogenesis. Nevertheless, in both cases the nucleus is the 
ultimate source of the zymogen granules. Mathews, in agreement 
with Nussbaum, arrives at the rather sweeping conclusion that 
the changes in the nuclei of the secreting cells are passive, the 
nuclei taking no active part in secretion or in zymogenesis. 
The active part taken by the nucleus in the production of the 
diastase granules certainly forms a very evident exception to this 
generalization and is a point in favor of the views of Heidenhain, 
Korschelt and others, who consider that the changes in position 
and size of the nuclei during secretion are signs of functional 
nuclear activity. 
There is considerable evidence that chromatin is the synthetic 
substance of the nucleus and in the elaboration of the metabolic 
Products acts somewhat in the manner of a ferment. In other 
words it brings about the union of certain elements without enter- 
ing into the synthesis itself, or becoming changed in its chemical 
nature. Mathews thinks that the fact of the cell threads ending 
in the chromatin points to this conclusion. The secretion or 
rather the hylogenesis of diastase seems to be a case exactly to 
the point, as here the process is strictly intranuclear. Pekel- 
haring (95) and Halliburton (’95), working from another view- 
point, have demonstrated that fibrin ferment is a nucleo-proteid, a 
form of chromatin. That the amylolytic granules, while in the 
nucleus, stain in the same manner and with the same intensity as 
chromatin, indicates that they have something in common with the 
fibrin-ferment. According to Macallum the nuclei of the pan- 
creatic cells have much to do with the formation of the enzyme. 
His experiments lead him to the conclusion that the chromatin 
elaborates a substance which he calls prozymogen. This finds its, 
Way into the cytoplasm and, combining with certain elements, 
forms the granules of the enzyme ; certainly a very good descrip- 
tion of the sequence of stages in the diastase cell. . 
The wide-spread occurrence of granules in secreting cells is 
worthy of note. Green (99) giving quite a number of examples 
in which this is the case. In the mucous glands of the frog’s 
