8 CONNECTICUT EXPERIMENT STATION, BULLETIN NO. 178. 
cable except perhaps on single trees used for ornamental pur- 
poses. 
Medication. Injecting various substances into the tree has 
been tried but with no success, as any substance sufficiently 
poisonous to kill the blight is injurious to the tree, and further- 
more it is difficult to make a tree absorb any very great amount 
of material injected into it. 
Cutting Infected Trees. The removing of all infected trees 
has been tried ‘but as with the other remedies its success has 
been only indifferent at the best, as it is hard to find all infected 
trees when scouting for the disease, and the few not found are 
sources of new infections. The expense and trouble of destroy- 
ing infected portions of the tree after cutting makes this method 
of control out of the question for treating chestnut woodland. 
Thus at present we are without any effective method of com- 
bating this trouble in the forest and at best are only partly 
successful with single specimens in a yard or park. 
DISSEMINATION OF SPORES. 
There are several ways in which the blight may be spread, but 
from our own observations it would seem that the wind and 
possibly birds, especially those which hunt for larve of insects 
in the bark, are chiefly responsible. It can be readily seen that 
when an affected tree is producing countless millions of such 
minute spores the wind will easily blow them to a considerable 
distance. This is especially true of the winter spores, which are 
forcibly ejected from the sacs in which they are borne. These 
spores lodging in a wound in the bark of a chestnut tree or 
being washed there by the rain would start a new infection of 
the disease. As the summer spores are produced in sticky 
masses, birds may pick them up on their beaks and feet and 
thus carry them to new localities. Other ways of dissemination 
are insects and transportation of diseased chestnut wood from 
one place to another. The fungus often produces spores for one 
or two years on cut wood especially when the bark has been 
left, so that diseased wood can be a source of infection for 
