R. A. STUDHALTER AND F. D. HEALD 
Summary 
Viable pycnospores of the chestnut blight fungus were found to 
be present on normal bark below lesions in numbers varying from o to 
1J2,222 per square centimeter of bark surface (1,111,176 per square 
inch). 
Of the 36 pieces of bark tested, only five failed to yield positive 
results, and four of these five were collected 14 days after a rain. 
Viable pycnospores were obtained in all but one of 24 tests made 
during December and January, when no spore-horns were present in 
the field. 
An abundance of viable pycnospores was obtained at as great a 
distance below a lesion as 70 cm., and it appears very likely that they 
could be obtained at much greater distances below cankers. 
Most of the tests were made one or two days after a rain; in one 
series, however, tested 14 days after a rain of 0.56 inch, positive 
results were obtained from five of the nine pieces of bark from which 
cultures were made. 
LITERATURE CITED 
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