923 : 
formed and Freurine-reducing substances do not appear in the liquid 
containing amygdalin. It was demonstrated that in this case amy g- 
dalin was absorbed and utilized by the mycelium because as the 
quantity of mycelium increased the quantity of amygdalin in the 
solution at the same time diminished. 
These apparently contradictory results of Puriewrrscn and of other 
investigators in analogous cases have fi€quently been a subject of 
discussion. Hékrissky') for instance says: “If during the metabolism 
amygdalin and corresponding glucosides, in a similar way as in 
vitro by emulsin, are first split up into compounds which are easily 
assimilated such as glucose, on one hand and into noxious compounds 
on the other hand, it may be expected that these poisons will be 
converted at once into other chemical compounds.” But this is a 
matter of uncertainty, Hérissey says and he does not give a definite 
opinion. 
W. Kruse’) is surprised at the said experiments of Purrewirscu 
and points to the fact that other investigators have not obtained the 
same results. The uncertainty about this subject made me take it 
up in order to try to clear it up. 
Solufions containing 2°/, amygdalin and the necessary inorganic 
nutriment were inoculated with spores of Aspergillus niger. The 
temperature during cultivation was 38°. 
Many times in the course of development the quantity of dry 
substance on one hand and the polarisation of the solution on the 
other hand were determined from which the assimilated amygdalin 
could be calculated. The mould layer, after being washed with distilled 
water, was therefore dried at 105° to constant weight. (Tab. I p. 924) 
My experiments confirmed the observation of Purtewitsc# that 
amygdalin is assimilated by the living mycelium, whilst the pro- 
duction of young mycelium occurs at the cost of the assimilated 
amygdalin. (Table 1). This table shows too that amygdalin is a 
better nutriment than glucose at least with regard to the dry weight 
of mould obtained. 
This conclusion agrees with results which I obtained before, viz. 
that the presence of a benzolnucleus in the assimilated organic 
chemical compound increases the quantity of mould formed at the 
cost of this nutriment. *) 
Formerly | demonstrated with great probability that in a special 
1) E. H. Húrissey, Recherches sur |’émulsine. Thése Paris 1899. 
2) W. Kruse, Allgemeine Mikrobiologie, 1910, p. 458. 
3, H. J. Waterman, Zeitschr. f. Gärungsphysiologie, Bd. 3, Heft 1 (1918). 
59* 
