218 
(line P }). In this case the element, whether added purposely or 
not ought to be present in the liquid. At a possible non-presence 
the ordinary utilisation of the intermediate products with the other 
elements would be retarded or even not take place at all, at least 
if the said element should have an essential and not a subordinate 
significance for the metabolism. Experiments in connexion herewith 
have, however, shown that such an element does not exist (See Table ID. 
TABLE II. 
50 cc. of nutrient liquor composed of tapwater in which is dissolved 2 9%/p 
anhydrous glucose, 0.15’) NHyNO3, 0,15’/, KH2PO,, and 0.1% crystallised magnesium 
sulphate. Temp. 33°. Inoculated with Aspergillus niger. 
Dry substance in mg (dried at 105° to constant weight). 
After, >| After After 5 days') of which the | After 7 days'), of which the 
4 days!) | 5 days!) | last day on dist. water (last three days on dist. water 
436 367 368 341 
439 353 314 
| | | 315 
For the utilisation of the intermediate products and the consequent 
decrease of the quantity of dry substance an absorption of any 
element from the nutrient liquor is thus no lunger essential ®) in the 
normal metabolism of Aspergillus niger. All elements needed for 
the metabolism of Aspergillus niger are accumulated in the young 
fungous material and when this gets older they are partly excreted °). 
Elements that are permanently accumulated, whilst the cells are 
growing older, do not exist. 
Dordrecht, May 1916. 
1) All the glucose is consumed. 
2) The element oxygen is excluded here. 
8) Represented in the Fig. by the lines PQ, PR, PS, PX ete PZisa particular 
but improbable case. 
