512 BOTANICAL GAZETTE [DECEMBER 
of zinc and manganese, the first publication of which has been reviewed in this 
journal.’s 
From recent work of RITTER*® and of HAGEM,”’ as well as from scattered 
observations in the older literature, it appears that the power of using nitrogen 
in the form of nitrite is widespread among filamentous fungi. further con- ’ 
tribution to this subject is made by Kossowr1cz,* who finds that Botrytis 
Bassiana, Penicillium glaucum, P. brevicaule, Mucor Boidin, Cladosporum 
herbarum, Phytophthora infestans, Aspergillus glaucus, A. niger, Isaria farinosa, 
and a species of Fusisporium grow readily on synthetic culture solutions 
containing potassium’As' thé sole source of nitrogen; and cane sugar, dextrose, 
or mannite as carbon compounds. The formation of ammonia could 
definitely shown to occur only in mannite cultures of Phytophthora infestans 
and in those of Fusisporium. In cultures containing sugars the ammonia 
reaction of Nessler’s reagent is not reliable on account of the similar reaction 
given by dextrose. It is erroneous, however, to conclude from the absence of 
the ammonia test that nitrites are not reduced to ammonia before being 
assimilated. The absence of ammonia merely shows that it is not produced in 
excess of the quantity used. In the absence of quantitative data showing the 
yields produced, the effect of nitrogenous substances in the tap water which 
the author used in his experiments cannot be easily estimated. 
Kossowicz and GROLLER”® have investigated the value of sulphocyanates 
as sources of nitrogen, carbon, and sulphur for fungi. The same species of 
It was found that in the absence of other nitrogenous compounds (except such 
as were introduced by means of the tap water and as impurities in the other 
compounds used) the fungi made a feeble growth which soon ceased in nutrient 
solutions containing ammonium, potassium, sodium, or iron salts of sulpho- 
cyanic acid. Traces of hydrogen sulphide were detected only in cultures of 
Mucor Boidin and occasionally in those of Aspergillus niger and A, glaucus. 
The conclusion that the fungi used in these experiments can obtain nitrogen 
from sulphocyanates would seem to need further support in view of the fact 
that in all cases there was a cessation of growth after a few days. The fungi 
made no growth when sulphocyanates were the sole source of carbon or of 
both carbon and nitrogen. A feeble growth appeared when the substance was 
the sole source of sulphur. Sulphocyanates seem to be only slightly toxic, 
although they cause a distinct depression of growth, yet even in a 10 per cent 

5 Bor. Gaz. 55:89. 1913. , 26 Rev. Bot. GAZ. 55:91. 1913- 
77 Rev. Bor. Gaz. 55:463. 1913. 
% Kossowicz, A., 2S epseeamery's durch Schimmelpilze. Zeitschr. Gérung> 
physiol. 2:5 a 
SOWICZ, ag und Groxter, L. von, Rhodanverbindungen (Schwefelcyan- 
verbindungen) als Kohlenstoft, Stickstoff, und Schwefelquelle fiir ee 
Sprosspilze (Hefen), und Bakterien. Zeitschr. Girungsphysiol. 2:59-65- 19 

