ENDOTHIA CANKER OF CHESTNUT 607 
Blight Commission, 1914) says that careful tree-surgery work will often 
save affected trees. 
With regard to the eradication measures to. be applied in the forest, 
the cutting-out method of Metcalf and Collins (1911:10-17) embodies 
the principles mentioned above. The method, although put into practice 
in Pennsylvania in 1912 and 1913, will not now, it seems, be demon- 
strated, since all concerted attempt at country-wide control has been 
abandoned. At the present time, however, we can theorize on the prac- 
ticability of the method with more certainty than was possible at the time 
of its original consideration in rort. 
The writers believe that the method would not have succeeded 
economically even if it had been vigorously prosecuted from the time 
of its proposal. In addition to the reasons given by Stewart (1912) 
and Murrill (1912) which in their opinion make the method impossible, 
later research has constantly added evidence of the important part played 
by numerous disseminating agents that must be reckoned with. Careful 
surveys and the elimination of all spot infections outside the affected 
region would accomplish temporary control. But even with a carefully 
executed quarantine on nursery stock and chestnut products, the chances 
of reinfection from a distance or reappearance at an old spot infection 
would necessitate constant resurveys, which, if thorough, would be 
expensive and could not even then be expected to absolutely eradicate 
the disease. The principal difficulty, however, would be the main line of 
advance, where on the one side nothing would be done and immediately 
adjacent complete control would be attempted by eradication. The 
immune zone suggested in this scheme is the only way of meeting this. 
Just how wide such a zone would have to be in order to obviate infection 
due to wind dissemination of ascospores would vary with conditions. 
The chestnut-free belt in the Catskill Mountains, varying from thirty 
to forty miles in width, has apparently furnished protection for the area 
west of the mountains. The mere felling and utilization of all the trees, 
however, in a zone twenty miles around the affected area as it was in 
tg911, would be an enormous task, consuming much time and money. 
Taking into consideration the work and the money required in order to 
put the whole scheme into operation, it does not seem logical to believe 
that the chances of success warrant the risk. 
Hope is expressed in a publication by Craighead (1912), who states 
that certain insects found eating the perithecial pustules of: the canker 
fungus may aid in eradicating the fungus. Ruggles (Penn. Chestnut 
Tree Blight Com., 1914), however, writes: “ The particular insect 
(Leptostylus maculata), carrying the 336,900 spores mentioned is one of 
the beetles named in a recent press notice of the United States Depart- 
