491 



formed. Moreover it is seen tiiat lliere is indeed in the beginning 

 of the development an inoi-ease in the dry matter as well as in 

 diastase, but that the increase in enzyme comes to a standstill, 

 whilst the fungus-mass continues to increase for many dajs. 



Do the experiments described indeed afford a proof that the 

 amount of diastase in the fungus increases during the first days 

 and then again undergoes a diminution? May it not be tliat the 

 culture-fluid, which is used for the extraction of the enzyme, undei-- 

 goes a slow change of such a nature as to accumulate a substance which 

 destroys the enzyme or at least opposes its action? Or conversely 

 may not there be some accelerator which is |)resent at the beginning 

 and first increases, and later diminishes? A decided answer to 

 such questions can only be given when the method has been 

 further worked out which was biiefly described at the beginning 

 of this paper. But nevertheless there are facts which make the 

 explanations suggested here very improbable. 1 therefore point out 

 that in all series of experiments the decrease in the anjount of 

 diastase does not take place regularly, but that later again a sudden 

 increase is observed. It is not readily conceivable that the compo- 

 sition of the culture-fluid should suddenly undergo such a change 

 that the sudden change in the figures could be thus explained. One can 

 only think of an increase of the amount of diastase within the cells of the 

 fungus. And when in this case nogreat influence on the figures for the 

 diastase can be assigned to the culture-fluid, then this cannot be 

 assumed in the other cases either. It may therefore be expected 

 with fairly great certainty that the general course of the curve of 

 figure 1 or 2 gives a picture of the actual quantities of diastase 

 which occui' in the mycelium of Aspeiyilbis niger. 



If we may accept the above conclusion as correct, then there follows 

 more from it. Firstly, if we disregard for a moment the later 

 irregularities of the cur\e a very quick initial rise is observable, 

 followed by an almost ecpially strong fall. The former would be 

 explained by the constant formation of more fresh enzyme, but the 

 fall? There hardly remains anything but the conclusion that des- 

 truction of enzyme is always going on within the cell; this des- 

 truction then in the fii'st days is compensated for and exceeded by 

 the new^ formation, which latter very quickly comes entirely to a 

 standstill or becomes so slight that it is far from being suflicient to 

 keep the (pianlity of enzyme at a level. 



I now return to the irregularities which are to be seen in the 

 falling part of the curve. It is seen from the first two tables that 

 after al)Out one month the amount of diastase in the fungus suddenly 



