759 
Into each Erienmnier flask of Jena glass (200 em?’ capacity) 50 em* 
of the above liquid was introduced and manganese in different 
concentrations was added. 
For the result see Table V. 
Quite as in the preceding experiment every nr. consisted of several 
flasks. Taking this into consideration, the extreme sensibility of 
Aspergillus niger as to manganese, already observed by BERTRAND, 
was with certainty confirmed. Without manganese hardly any spores 
are formed after four days. 
In spite of the observed favourable influence of manganese on the 
production of spores no important modifications in the metabolism 
of the carbon occur (Table V). 
We may thus conclude that the numbers given by Brrtranp !) 
for the dry weight with and without addition of manganese relate 
only to the velocity of the metabolism. 
is it necessary or desirable to distinguish elements such as man- 
ganese from others as carbon, nitrogen, ete. which occur in the 
organism in great percentages? Have we to reckon manganese 
among the purely catalytic elements, in opposition to carbon as a 
plastic one? In my opinion there is no sufficient reason for such a 
marked separation. The only important difference is that elements 
as manganese form an extremely small permanent percentage of 
the organism. It is, however, very well possible that this difference 
is only apparent. The circulation of manganese may for instance 
be much quicker than that of carbon, so that the concentration in 
one special cell may for a time have been relatively high. It is not, 
however, possible to detect this by analysis of the whole mould layer. 
5. Action of zinc. 
Since Raurin had already supposed that zine acts favourably on 
the weight of mould, Javirrier °) showed with certainty that small 
quantities of zine considerably increase this weight. At the same 
time he proved that zine is fixed in the mycelium *). Moreover, 
BerTRAND and JaviLLigR *) studied the joint action of zinc and man- 
1) BerTRAND G. r. 154 (1912) p. 616. 
2) JAVILLIER, Sur l’influence favorable de petites doses de zinc sur la végétation 
de ! Aspergillus niger, Cr. 145 (1907) p. 1212, 
Also compare BERTRAND et JAVILLIER, Sur une methode permettant de doser de 
très petites quantités de zine C. r. 143 (1906) p. 900; 145 (1907) p. 924. 
3) Sur la fixation du zinc par !’ Aspergillus niger. G. rv. 146 (1908) p. 365. 
4) BERTRAND et JAVILLIER, C. r. 152 (1911) p. 900; C. r. 153 (1911) p. 1337. 
Cf. also Ann, de I’Inst. Pasteur T. XXVI (25 Juillet 1912) p 515. 
