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trees, especially the Conifere and Cupuliferze. In some cases 
they form a true mycorhiza (fungus root).” He does not seem to 
think that these fungi are of any use to the plant, but, on the 
contrary, more or less harmful by taking nourishment properly 
belonging to the plant. The hypertrophic condition of the infested 
root is probably caused by an irritating substance secreted by the 
fungus. But many forest trees of different varieties showed no 
traces of the root fungus. 
In 1887 Hellriegel and Willforth concluded a long series of 
experiments which led to a new hypothesis in regard to the free- 
nitrogen-assimilating function of the Leguminosz. Notes on these 
experiments dated back from the years 1862 and 1863. They 
were conducted under the direct supervision of Hellriegel. Among 
his assistants were H. Roemer, R. Giinther, H. Moeller and G. 
Wimmer. Without going into details their conclusions may be 
summed up as follows: 
1. Leguminous plants develop in sterilized soil. 
2. Addition of sterilized nitrates increased their growth. 
3. In harvest time there was no excess of stored nitrogenous 
material which could have come from any other source than the 
soil. 
4. In non-sterilized soil the Leguminosz developed better than 
in sterilized soil, especially if there was added a solution made 
from soil in which leguminous plants had grown (culture soil 
solution). 
5. In harvest time there was found stored up in the plant an 
overplus of nitrogenous compounds which could not have been 
taken from the soil. 
6. Leguminous plants in sterilized soil to which only a small 
amount of the above mentioned culture soil solution was added 
showed this overplus of nitrogenous compounds. 
7. One and the same Leguminous variety did not give like 
results with different culture soil solutions. 
8. Leguminose in non-sterilized or sterilized soil inoculated 
with the culture soil solution developed tubercles. 
9. Leguminosz in sterilized soil developed no tubercles. 
10. In the same plant, if one side of the root was dipped - 
