CONTROL OF THE CHESTNUT BARK DISEASE, Zs 
Some of the symptoms are quite prominent. Limbs with smooth 
bark attacked by the fungus soon show dead, somewhat discolored, 
sunken areas (occasionally with a raised margin), which continue to 
Fic. 2.—Large chestnut tree partly killed by the bark disease. Note the sprouts 
with leaves near the top, the dwarfed leaves on the lower right-hand limb, and 
the healthy lower branches with leaves. 
enlarge and soon become covered more or less thickly with yellow, 
orange, or reddish-brown spots about the size of a pinhead. These 
spots are the pustules of the fruiting fungus. In damp weather or 
in damp situations, masses of summer spores are extruded in the 
Fic. 3.—Diseased chestnut bark showing pustules and form of discharge 
of summer spores in damp weather. (Magnified 3 diameters. ) 
form of long, irregularly twisted strings or “ horns,” which are at 
first bright yellow to greenish yellow or even buff, becoming darker 
with age (fig. 3). If the lesion is on the trunk or a large limb with 
very thick bark there is no obvious change in the appearance of the 
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