1048 
2°/,, at ieast 6 mers. should have been found, a quantity which 
ean with certainty be indicated by “Fehling”. 
This proves that there is no question of a considerable perma- 
nent adsorption at the outer surface of the protoplasm, but that 
it behaves more like a semi-permeable wall towards the glucose. 
The same experiment was once more repeated, but this time with 
a 2°/ glucose solution without anorganic substances, with shaking 
for two hours. Now, too, the mould proved to contain no glucose. 
A duplo-experiment gave only traces ot glucose. 
Hence the adsorption in Aspergillus niger is of no significance for 
the accumulation of nutrient substances. 
Now it is a matter of course that the first stage of the accu- 
mulation is an adsorption, but it evidently escapes observation. The 
high plastic’ aequivalent in tbe beginning pointing to an extensive 
fixation of carbon-containing material, relates to a further stage 
of assimilation. 
The food has then already passed into other compounds, e. g. into 
ely kogen. 
If the observations have ascertained that physiologic processes 
may be represented by an adsorption curve, this cannot be explai- 
ned by accepting an adsorption in the first part of the process but 
it may be a consequence of what happens in a later stage. 
Such an adsorption curve does not in general represent a simple 
process; it is more a combination of a whole series of successive 
physical and chemical phenomena. 
In the study of the nitrogen results have been obtained corre- 
sponding to those found with the carbon. 
It has namely been observed that also the nitrogen compounds 
used for the nutrition, are accumulated in the organism in a way 
not yet explained. First I convinced myself that the plastic aequi- 
valent of the nitrogen at the end of the experiment is subject to 
only slight changes, as is shown in table I. 
Compare for this nrs. 1 with 2 and 3, 4 with 5, 9 with 10pm 
with 12, 13 with 14. Secondly the quantity is independent of 
the nature of the source of carbon provided the weights of the 
mould be alike. For the levulose we find the same numbers as for 
the glucose. Lowering of temperature does not (nrs. 9 and 10) 
influence the rate of nitrogen of the mould, nor is it changed by 
addition of boric acid (nrs. 11 and 12). 
Table II gives a view of the quantity of nitrogen fixed in the 
mould layer at various periods of development. 
After 3 days the accumulation of nitrogen is of importance. Per 
