1906] KAUFFMAN—A MYCORHIZA-PRODUCING FUNGUS Bis 
But it was soon found that the reddish network extended along 
definite paths. Beginning with a tiny rootlet, the fungus was fol- 
lowed to a rather large root, apparently growing from a hickory. 
On examination, however, it was found that the mycorhiza-bearing 
root passed the hickory, and that all the roots of the hickory examined 
were devoid of a colored mycorhizal fungus. On the other hand, 
the root in question was now easily traced to a clump of red oaks, 
of second year growth, which were distant at least 544" from the 
starting point. Besides the hickory, the roots of a Crataegus which 
crossed the oak roots were likewise devoid of the fungus in question. 
The red strands were attached only to the small rootlets, and 
where the roots extended below the black soil into the yellow subsoil 
the mycorhiza gradually disappeared, facts which were known to 
FRANK, STAHL, and others. The leaf mold along with the remains 
of last year’s leaves forms a thin covering beneath which the young 
buttons of the fungus are started. 
About twenty paces down the slope, another troop of the same 
species of Cortinarius was found. These came up only 30°" away 
from a fine young sugar maple and close to one of its main roots. 
Expecting that they were probably attached to the roots of an oak a 
short distance away, I dug down carefully and found to my surprise 
that the strands which were very luxuriant here were attached to the 
rootlets of the sugar maple; even the small roots growing directly 
from the base of the trunk were thickly beset by the strands. The 
Sporophores were loosened and the attachment of the strands followed 
from the stipe to the rootlets and thence to the tree. Several days 
later on visiting the same hill, two more sporophores were found on 
the north slope of the hill, again with the characteristic strands, and 
connected with a red oak. 
T had to leave Ann Arbor at this time, and not until I came back 
in September did I have any further opportunity to make observa- 
tions. On October 30 the slope was dug over for a considerable 
‘rea around the original habitat of the Cortinarius in question. 
The roots of the same maple were found to be hung with the reddish 
Strands in all directions, just as luxuriant apparently as in the early 
Summer. Here, also, other roots crossing or intertwining with the 
maple roots—with one exception—were not affected by the fungus. 
