ENDOTHIA CANKER OF CHESTNUT 597 
Metcalf and Collins (1909: 49-52) take up in detail the means of control 
of the disease. After stating that the distribution of the fungus to distant 
points would be accomplished largely by the shipment of diseased nursery 
stock, they point out the necessity of rigid inspection of nursery stock 
shipped into uninvaded territory. They also advise a campaign of 
education in order to acquaint the public with the nature and appearance 
of the disease. They then point out the necessity of promptly cutting 
and burning newly affected trees so that spot infections may be arrested. 
They say: ‘‘ 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 care- 
fully 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 
(where the size of the branch permits) beyond the characteristic, often 
fan-shaped, discolored areas produced by the growing fungus in the 
inner bark. All small infected twigs or branches should be cut from the 
tree, the cut being made well back of the diseased area. A pruning knife 
with an incurved tip, a hollow gouge, or any other clean-cutting instru- 
ment will serve for cutting out diseased spots. . . . The paint or 
tar may be applied by means of a good-sized brush, care being taken to 
cover every part of the cutting.” (See Figs. 96 and 97.) 
It remained for Metcalf and Collins (1911: 10-24) to suggest definite 
methods for arresting the country-wide progress of the disease. They 
outlined their method of scouting and cutting-out in detail (pages 12 to 
17 of reference cited). The procedure is summarized thus (page 24): 
“The only known practical way of controlling the disease in the forest 
is to locate and destroy the advance infections as soon as possible after 
they appear and, if the disease is well established near by, to separate the 
area of complete infection from the comparatively uninfected area by 
an immune zone. Advance infections should be located by trained 
observers and destroyed by cutting and burning. As the disease develops 
almost entirely in the bark, this must be completely destroyed (burned). 
“In order to carry out the above methods it is essential that the several 
States concerned secure necessary legislation and appropriations, follow- 
ing the example of Pennsylvania, as no law exists whereby the Federal 
Government can undertake such work and cooperation among private 
owners without state supervision is impracticable.’ 
The method proposed led to much discussion among pathologists. 
There were a few who openly criticized the method as impractical, and 
