442 CONNECTICUT EXPERIMENT STATION REPORT, IQI2. 
PREVENTIVE EXPERIMENTS. 
Earlier Experiments. Murrill tried to control the chestnut 
disease, when it was first discovered at the New York Botanical 
Garden, by cutting down and destroying the badly infected trees 
and by cutting out cankers on those less seriously injured. He 
found this did not prevent its further spread. Writing in 1908, 
he (48) says: “Preventive measures have apparently not 
affected it in the slightest degree. Pruning of diseased branches 
has evidently failed to check it even in the case of very young 
trees. Branches have been carefully removed, and wounds 
covered, leaving trees apparently entirely sound, but upon 
inspection a few weeks or a few months later, they would be 
found badly diseased.at other points.” Merkel, at the New 
York Zoological Park, also tried to control the trouble by cut- 
ting down the badly infected trees and by spraying with Bor- 
deaux mixture, but little or no benefit resulted from his efforts. 
Metcalf undertook experiments to control the trouble on 
Long Island in a region where it was very bad. In 1909 he 
and Collins (36) say: “At present it is impossible definitely 
to record general beneficial results from any of the sprayings 
which have been undertaken or have been under observation. 
This may in part be due to the fact that it is yet too early to 
judge satisfactorily of the results, and in part perhaps to the 
infrequency of sprayings. * * * Almost the only treatment 
that can at present be safely recommended as surely retarding 
the spread of the disease, to a greater or less extent, is one 
which will never be of practical use except in the case of 
orchard trees or certain valuable ornamental trees. It consists 
essentially in cutting out the infected branches or areas of bark 
and carefully protecting the cut surfaces from outside infection 
by means of a coat of paint or tar. This cutting must be 
thoroughly done and the bark of every infected place entirely 
removed for a distance of at least an inch (when the size of the 
branch permits) beyond the characteristic, often fan-shaped, 
discolored area produced by the growing fungus in the inner 
bark.” In a later report, they also advocate that when the inner 
bark is badly infected “at least two or three annual layers of 
wood beneath the diseased bark must also be gouged out.” 
Later Experiments. In a bulletin published in October, IgIl, 
Metcalf and Collins (38, p. 10) advocate fighting the chestnut 
