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depressed below the general surface of the tuber, due to the drying 
and breaking up of the tissue. Very frequently only one or two 
such sunken areas, which vary from half an inch to an inch across, 
tuber, proving that mycelium migrates from the primary diseased 
areas, and that portions of the tuber apparently free from disease 
“sets” any tubers showing signs of the disease, as is too frequently 
done, after the obviously diseased portion has been cut away. 
The sclerotia and mycelium, in the absence of fruit, were 
described by Frank under the name Phellomyces sclerotiophorus. 
1, Tuber showing diseased depressed areas and minute sclerotia 
2. Spondylocladium atrovirens x 300. 
A sclerotium on the surface of a tuber x 50, 
12002 
