1913] GODDARD—SOIL FUNGI 251 
nitrogen. In the first four species, he found a nitrogen gain, 
running as high in one case as 10.53 mg. in a socc. culture of beet 
sugar decoction. The last three species showed negative results 
throughout. 
TERNETZ first isolated a pycnidium fungus from the roots of 
Oxycoccus, reporting that it had the power of fixing free nitrogen to 
the amount of 6-10 mg. per 1 gm. of dextrose used. Later, the 
same author (19) contributed another paper on other pycnidia 
fungi, isolated from the roots of Ericaceae and referred to the genus 
Phoma. These were cultivated on nitrogen-free media based on 
Wrvocrapsxy’s formula, but using varying quantities of sugar, 
phosphate, and magnesium. In a full and painstaking investiga- 
tion, the author reports free nitrogen assimilated by the 5 species of 
Phoma as follows: 2.17, 3-99, 10.9, 18.0, 22.1 mg. per I gm. o 
dextrose used.. In the same investigation, Aspergillus niger and 
Penicillium glaucum were reported to gain 1.71 and 3.8 mg. 
respectively per 1 gm. of dextrose used. 
Four years later, FRoELIcH contributed a careful study of four 
fungi isolated from decaying stems and leaves. The forms were 
identified as Alternaria tenuis N ees, Macrosporium commune Rbh., 
Hormodendron cladosporium .Sacc., and Cladosporium herbarium 
Link. These were cultivated on a medium similar to WurNo- 
GRADSKY’S for Clostridium pasteurianum, with quantities of dex- 
trose varying from 2 to 5 gm. per 1oocc., and the cultures were 
aerated by air freed from combined nitrogen. The author reports 
nitrogen gains of 2. 56-8.92 per 1 gm. of dextrose used. FROELICH 
also reported confirmation of TERNETz’S results on Aspergillus niger 
and Penicillium glaucum, although much smaller gains are report 
by Froeticu. 
Perhaps the latest positive results for nitrogen-fixation by fungi 
have been contributed by LaTHam (20), who worked on Sterig- 
macystis nigra (Aspergillus niger), cultivated in solutions containing 
ammonium nitrate, potassium dihydrogen phosphate, magnesium 
sulphate, sugar, and a trace of iron. Some of the cultures were 
modified by the addition of zinc sulphate, but this was reported 
to have an inhibiting effect on the nitrogen-assimilating power. 
The cultures without zinc sulphate are reported to fix nitrogen 
