534 BULLETIN 347 
twenty-five feet and were bearing excellent nuts when attacked in 1910, 
but all have succumbed. The crosses of Asiatic and native, fewer in 
number, showed greater resistance but all have been seriously affected. 
The chinquapin-European hybrids are readily affected but have great 
recuperative powers, bearing nuts the second year on suckers springing 
from the bases of diseased stems. Chinquapin-native crosses with the 
exception of the Rush chinquapin-—a probable natural hybrid found 
wild in Pennsylvania — appear very susceptible and do not as readily 
recover. The wild chinquapin itself appears measurably resistant, several 
individuals, including two Rush chinquapins, thriving for years with no 
signs of disease though constantly surrounded by infection. 
“The Asiatic chestnuts, and the chinquapin-Asiatic hybrids, are 
plainly highly resistant. Few have shown any appearance of infection 
and when noticeable the injury is quite local in character. Second 
generation seedlings of chinquapin-crenata crosses show no disease at all 
though always exposed to infection.” 
Morris (1914) reports that five trees of the species C. mollissima have not 
been affected, although American trees have died all around them. Speci- 
mens of C. alnifolia also have remained free from the disease. 
In brief, it may be said that there is no species of Castanea which is 
wholly immune. Some varieties show marked resistance, especially 
Asiatic varieties, and Metcalf (1914) claims apparent immunity for certain 
strains. On the other hand, no species outside the genus Castanea is 
known to be seriously affected. 
The species of Castanea are confined to the northern hemisphere and 
are widely distributed through their range. Schneider? states that there 
are five species which are very closely related one to the other, in part 
probably representing only geographical varieties. The following species 
are recognized: C. crenata, of Japan and Central China; C. sativa, of 
southern Europe and northern Africa, and eastward to Persia; C. dentata 
and C. pumila, of eastern and southern United States. A species C. 
mollissima, of which little is known, has been described from China. 
Many varieties from Europe, Japan, and China have been introduced 
into the United States for orchard culture. Taylor® states that the 
European chestnut was introduced into ‘this country in 1803 and the 
Japanese chestnut in 1876. Corsa,‘ speaking of the European and the 
Japanese species, states: ‘‘ Both species can be grown in portions of 
this country, either as seedlings or as grafted trees on American stock. . . 
The majority of imported trees and seedlings raised in this country from 
“Schneider, C. K. Handbuch der laubholzicunde 12156. 1906. 
3 Taylor, W. A. Bailey’s Encyclopedia of American horticulture 1: 204. 
" a Si W.P. Nut culture in the United States. U.S. Agr. Dept., Pomol. Div. 1896. (Unaumbered 
