1056 
These results which, as experiments have proved, hold also good 
for a few other examined organisms, show that in the literature the 
influence of the adsorption is often overrated *). 
In order to test the obtained views about the metabolism of the 
nitrogen the following experiments were made (table VI). 
The quantities of added ammoniumnitrogen differ very much in 
the five series of experiments. In D there is just sufficient to satisfy 
the first wants (20.9 mers), in E was an excess of nitrogen, whilst 
in C, B and A there was a deficit of nitrogen relatively to the 
assimilated glucose. Still in B and C the additions were sufficient to 
satisfy the requirements of a mature mould layer. 
In A this was not, however, the case and the quantity of nitrogen 
was even smaller than that fixed in an old mould culture containing 
little glykogen and obtained at the expense of 1000 mgrs. glucose. 
To this it must be ascribed that the assimilation of glucose is 
slackened. After 9 days 20°/, is still unused. Fixation of nitrogen 
from the air could not be observed in this experiment, neither for 
A, nor for B or C, whilst yet these series of experiments might in 
particular come into consideration for an eventual fixation of atmos- 
pheric nitrogen in relation to the mentioned deficit in the nutrient 
solution. In the referring literature, however, are many statements 
tending to prove the contrary. 
We further see that also the velocity of glucose assimilation in 
B is diminished although the general course of the process of nitrogen 
fixation remained the same; a high nitrogennumber at first which 
for all the series decreased with the time to 2 to 3. 
The nitrogennumber of A. B, and C, and in slight degree also of 
D, was in the beginning bound to a certain limit determined by 
the added nitrogen and the mould. 
Series A has a deficit of nitrogen with regard to the quantity of 
assimilable carbon ; series E is characterised by a deficiency of carbon 
as to the quantity of fixed nitrogen. i 
We should still point to the association of the plastic aequivalent 
of the carbon and the nitrogennumber. If the former is high this is 
also the case with the latter and the reverse. 
Summary. 
1. The nitrogen fixed in the mature mould is proportional to the 
plastic aequivalent of the carbon independently of the nature of 
the carbon as well as of that of the nitrogen. 
1) See also W. Retnpers and D. Ley, These Proceedings, 1912, p. 482. 
