1913] GODDARD—SOIL FUNGI 253 
out two series of experiments, involving about 400 flask cultures 
with a great variety of culture media. Analyses showed that in 
no case was there fixation of atmospheric nitrogen, except possibly 
in certain cultures of Aspergillus niger. In many cases, DUGGAR 
reports there was a loss of nitrogen, which he attributes, usually 
at least, to the production of gaseous nitrogen. A third series of 
experiments is referred to, in which additional fungi have been 
tested and the experiments of other investigators have been 
duplicated with negative results. 
It is beyond the province of this paper to consider the mycorhiza 
fungi, any more than merely to refer to the work of HittTNER (27), 
FRANK (28), and others, who have reported nitrogen-fixation by 
such fungi. 
Discussion of these apparently very conflicting results will be 
reserved till a later part of this paper, the purpose here being only 
to give a brief historical review of the work on this problem up to 
the present time. 
The investigation described in this paper was begun several 
years ago, under the direction of Professor J. B. Pottock at the 
University of Michigan. The following purposes were in mind: 
(x) to determine what species of fungi live habitually in an ordinary 
agricultural soil; (2) to study their distribution as to depth and 
nature of the soil; and (3) to begin some study of the part they 
play in soil fertility. After isolating and making'a study of about 
17 species, attention was turned to the problem of nitrogen-fixation, 
since it was thought, from our knowledge of bacteria, that if any 
fungi possessed nitrogen-fixing power, such forms might well be 
looked for in the soil. Furthermore, if any soil fungi were found to 
fix nitrogen to any marked degree, such a fact would have important 
bearing on soil fertility, as well as a large interest from the purely 
Physiological standpoint. 
II. Isolation and identification of soil fungi 
HISTORY OF SOIL FUNGI INVESTIGATIONS 
“Although many of the fungi living in the soil have been known 
for some time, and many attempts have been made to isolate 
mycorhiza forms, little work seems to have been done previously 
