New York AGRICULTURAL EXPERIMENT STATION. TEL 
On August 3 while peeling some scabby potatces for potato 
agar we observed that some of the so called “‘ deep scab ” ulcers 
were filled with mycelium composed of: rather coarse hyphe. 
Microscopic examination showed the hyphz to be those of 
Rhizoctonia. These tubers had been bought at a grocery in 
Geneva. Other tubers were then obtained from other groceries 
and also direct from potato fields in the vicinity of Geneva, and 
it was found that Rhizoctonia hyphe are of frequent occurrence 
in scab ulcers. 
The next advance made was the discovery of the Rhizoctonia 
sclerotia on the tubers and stems. On September 21 Mr. Rolfs 
found, in a potato field near Geneva, a tuber bearing a few 
sclerotia of Rhizoctonia. The following day the field was re- 
visited and carefully searched. The crop had been harvested 
several days earlier, and in the interval rain had washed the dirt 
from such tubers as had been overlooked and also from the 
stems of the plants which were left in the field. This facilitated 
the search and we soon gathered about 30 tubers bearing sclero- 
tia. See Fig. 5. Then we began looking for sclerotia on the 
stems and had little difficulty in collecting about 25 good speci- 
mens. One of these is shown in Fig. 6. Having once seen the 
sclerotia on the tubers it was easy to find them on almost every 
lot of tubers examined. We found them, oftentimes in great 
abundance, on tubers offered for sale at the groceries in Geneva, 
Poughkeepsie and Ithaca. A wagon load of potatoes offered 
for sale at Ithaca was so completely overrun with Rhizoctonia 
that it is doubtful if there could have been found in the entire 
load a single tuber which did not bear one or more sclerotia. 
Some of the tubers showed several hundred sclerotia each. 
These tubers were of the variety Rural New Yorker No. 2;.and 
in other respects they were fine, being of large size and almost 
entirely free from scab and rot. ‘They were grown at Slaterville, 
near Ithaca. . A load of potatoes on the streets of Sayre, Penna., 
was examined and found to contain a considerable number of 
tubers bearing sclerotia. We have also seen the sclerotia on 
tubers grown at Mattituck and Cutchogue, Mr, A. D. Selby has 
