the blight fungus will fruit more readily on such material than on 
wood. Fans of blight mycelium sometimes can be seen on such 
shipped material. 
29. In considering the question of preventing or retarding the 
spread of the blight over Europe and the relative danger of different 
means of spread, one must realize that the means of long-distance 
spread in many cases are not known. Three introductions of the 
blight into Europe are known. The first infection, reported in 1923 
in a botanical garden in Belgium, was stopped by its removal. The 
second, reported at Genoa in 1938, origin unknown, was widely 
distributed when found. It may have come in on Japanese chestnuts 
or on some shipment of wood products from the United States. The 
third, near Bilbao, Spain, resulted from importation of chestnut 
seed direct from Japan. 
H, BLIGHT-RESISTANT EUROPEAN CHESTNUTS 
30, In my brief examination of infected chestnut stands in Italy 
and Switzerland, I noticed some trees that were being killed much 
more slowly than others. However, I noted nothing that gave me any 
hope that any considerable number of European chestnuts would 
ultimately escape being killed by the blight. Near Bilbao, Spain, 
one European chestnut in a blight-infected stand of Asiatic chest- 
nuts had been exposed to the disease for many years and had 
abundant growth of the fungus in its outer bark without any damage 
to the cambium region. American chestnuts sometimes reacted in 
this way but were finally killed bythe disease. In the United States , 
tests of Russian chestnuts from the Caucasus Mountains indicated 
that they are highly susceptible to blight, just as most other 
European chestnuts from different countries growing in the United 
States have been. However, the natural survival of a few European 
chestnuts in the United States indicates that they are more resistant 
than the American. 
31. Italian authorities have collected many varieties and strains 
of the European chestnut from different countries, to determine 
the more resistant ones. The best of these will be valuable for 
crossing with the best of the Asiatic chestnuts. 
I, RESISTANT ASIATIC CHESTNUTS 
32. In general Chinese chestnut, Castanea mollissima, and 
Japanese chestnut, C. crenata, are very resistant to chestnut 
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