1913] GODDARD—SOIL FUNGI 277 
which allowed entrance of air only through U-tubes containing 
concentrated sulphuric acid. 
5. Cultures of one of these four fungi (Myceliophthora sulphurea) 
were made in Erlenmeyer flasks containing solutions with varying 
quantities of ammonium nitrate, to see whether nitrogen-fixation 
would not be possible when 
growth was started by 
small quantities of com- 
bined nitrogen. These 
cultures, each containing 
50 cc. of the nutrient solu- 
tion, were left exposed to 
the laboratory air, being 
closed only by cotton 
stoppers. 
The media for all these 
cultures were made up by 
the use of ammonia-free 
water, as shown by tests 
with Nessler’s reagent. 
This water, for some cul- 
tures, was prepared by a 
second distillation of dis- 
tilled water, to which had 
been added a small quan- 
tity of sulphuric acid. The 
first part of the distillate 
was always discarded as an 
extra precaution. Some of 

Fic. 15.—Trichoderma Koningi Oudem.: a, 
hyphae with conidiophores, X80; 5-d, conidio- 
phores with conidiiferous cells and conidial 
heads, 380; e, conidia, 380. 
the cultures were made with extra pure, so-called ‘‘conductivity 
water” obtained from the chemical laboratory of the University of 
Michigan 
The chemicals used in all the investigations -were strictly C.P. 
Most of them were marked “‘Kahlbaum.” Furthermore, they were 
all submitted to chemical analysis, which showed all to be nitrogen- 
free except the dextrose, which contained 0.25 mg. of nitrogen 
