112 REPORT OF THE BOTANIST OF THB 
sent us from Wooster, Ohio, potato stems and tubers bearing 
Rhizoctonia sclerotia, showing that the fungus exists in that 
State. Specimens have also been received from Prof. J. F. Dug- 
gar, Auburn, Ala., Mr. F. M. Rolfs, Fort Collins, Colo., and Mrs. 
F. C. Stewart, who found it at Bassett, Iowa. In short, during 
the past season many observations on potatoes have been made 
in different parts of New York State, and Rhizoctonia has almost 
always been found in greater or less abundance. Moreover, it 
occurs in Alabama, Colorado, Iowa, Ohio, arid Pennsylvania, and 
is probably very generally distributed. Recently the sclerotid 
have been found abundantly in the markets of Washington, 
D. C., on New York and Michigan potatoes, and also to a slight 
extent on one variety of potatoes grown in Maryland. 
We have the following proof that the Rhizoctonia disease of 
potatoes existed at Ames, Iowa, as long ago as 1890. In the 
summer of 1890 Mr. F. A. Sirrine, at that time Assistant Bot- 
anist at the Iowa Experiment Station, investigated a potato 
disease which was doing serious damage on the Station farm. 
He found the subterranean parts of the affected plants covered 
with a certain fungus which he at once. suspected of being the 
cause of the trouble. He was unable to identify the fungus. 
In the course of the investigation an important insect enemy of 
the potato, the potato-stalk weevil, was discovered! in connec- 
tion with the disease, and as it appeared that this insect was 
responsible for at least the greater part of the trouble, attention 
centered upon it and the fungus was allowed to pass into obliv- 
ion. Fortunately, Mr. Sirrine made and preserved a camera- 
lucida pencil drawing of the fungus. This drawing shows that 
the fungus studied by Mr. Sirrine was undoubtedly a Rhizoctonia. 
We have inked in the drawing, without altering it in the least, 
and publish it herewith. See Fig. 7. 
The Rhizoctonia attacks only the subterranean parts of the 
potato plant. The hyphe occur in the medulla, where they are 
for the most part very slightly, if at all, colored, and on the out- 
side of the stem and on the roots, where they are often light 

*See Iowa Exp. Sta. Bull. 11: 490, 
