ON THE MYCORHIZAS OF FOREST TREES 
57 
Russula emetica Fr. and Russula fragilis (Pers.) Fr., yet it differs from 
both of these. It is not so fragile as R. fragilis and the cuticle does 
not peel off so easily. The gills are more crowded than in R. emetica. 
Most of all, it differs from these two species in the color of the spores, 
which in R. emetica and R. fragilis are white, while in this mycorhiza- 
forming species they are creamy. A peculiar thing about this Russula 
Ik. 
Text-fig. i. Sporophore of Russula attached to mycorhizal root. 
is that the sporophores are very apt to be deformed. Whether this is 
due to the presence of a parasite has not been determined. After this 
first crop of fruiting bodies had disappeared only four specimens were 
found during the rest of the season. The same form has been collected 
several times, however, in another locality, by Professor Kauffman. 
On August 12 a dozen sporophores of Boletus scaher Fr. var.fuscMs 
were growing under the Betula from which I had made regular collec- 
tions of mycorhizas. When these were dug up, evidence was found 
in every case, of a connection with the mycorhizas, and in several cases 
an actual connection was easily seen. Later in the season another 
crop of these mushrooms was found in the same place, and their 
connections with mycorhizas were again verified. At the same time, 
