1913] GODDARD—SOIL FUNGI 301 
conditions. While this question was only incidental in this investi- 
gation, the experience with these fungi under quite a ‘variety of 
culture conditions makes it hard to think that this can be a satis- 
factory explanation. Variations did, indeed, occur to some extent, 
but in all cases each form retained its distinct species characteristics, 
and showed no signs of nitrogen-fixation under any of the conditions. 
If nitrogen-fixation is finally established for any fungous forms, 
it seems probable that the character of the nutrient material sup- 
plied may be found to be an important factor. It is not felt that 
this investigation supplies sufficient data along this line to permit 
final conclusions. There is also the possibility, as already sug- 
gested, that the nitrogen-fixing power may be found to be con- 
fined wholly to the mycorhiza forms. 
IV. Summary of results 
This series of investigations would seem to justify the ‘laine 
generalization of results: 
1. Many species of fungi live habitually in the soil, carrying 
out their life history there, either in whole or in part. A consider- 
able number of these have been found, so far, only in the soil. 
2. These fungi are, at least to quite an extent, uniform in differ- 
ent soils, and, unlike the bacteria, appear to be rather uniformly 
distributed at different depths, at least as low as 14 cm. 
3- Tillage and manuring seem to produce little change in the 
number or kind of these fungi. This conclusion is not regarded as 
final. 
4. These fungi may be cultivated and isolated as pure cultures, 
without interference from bacterial growth, by the use of 20-30 
per cent of gelatin in the culture medium. 
5- None of the forms studied, including at least 14 species, 
shows any power of assimilating free nitrogen when grown in 
nitrogen-free media under the conditions of these investigations. 
Myceliophthora and probably Fusarium show no such power even 
in nitrogen- -containing media. 
6. Myceliophthora when growing in nitrogen-containing solu- 
tions assimilates different proportions of nitrogen in different con- 
