ch usually finds entrance to the
tree through wounds in the bark. The mycelium or mass of fungous
filaments gradually spreads through the bark in much the same manner as
mold spreads over and through a piece of bread, even penetrating the
wood to a depth of sometimes five annual rings. The spread of the
fungus, resulting in the cutting off of the sap flow, is the immediate
cause of the wilting and dying of the leaves and branch above the point
of girdling. This wilting of the leaves, followed later by the death of
one branch after another as the fungus spreads, has given rise to the
term "blight" of the chestnut trees.

The danger signals which the chestnut tree displays when diseased are
not a few. In summer, when the tree is first affected, the leaves turn
yellow-green and wilt, later turning brown. Small burs and withered
leaves retained in winter are some signs of the diseased condition of
the tree. At the base of the blighted part a lesion, or reddish brown
canker, is usually found. This lesion may be a sunken area or, as is
frequently the case, a greatly enlarged swelling, known as a
hypertrophy. After a branch has become completely girdled sprouts or
suckers are very apt to be found below the point of girdling. In old
furrowed bark on the main trunk of the tree the presence of the disease
is seen in the reddish brown spore-bearing pustules in the fissures. In
determining the presence of the fungus in the furrowed bark of old
trees, one must learn to recognize the difference between the light
brown color characteristic of fissures in healthy growing bark, and the
reddish brown color of the fungus. When the disease has been present
several years the bark completely rots and shrinks away from the wood,
and when the bark is struck with an axe a hollow sound is produced.

Many of the owners of chestnut trees throughout Pennsylvania do not
acknowledge that a fungus is causing the death of the trees. They state
that since they have found white grubs or the larvae of beetles in
nearly every tree that dies, that it has been the larvae that killed the
tree. It is acknowledged that generally white grubs are found in dying
chestnut trees, and that in nearly all of the large cankers or lesions
these grubs are present. However, if one will take the pains to examine
the small twigs and branches or the new shoots rising from the stumps,
that are diseased, he will not find the grubs present.

Second, what is to be done with dis