414 CONNECTICUT EXPERIMENT STATION REPORT, IQI2. 
is still advanced only tentatively. * * * Chester’s Cytospora 
on a Japanese chestnut noted at Newark, Del., in 1902, may 
have been the bark disease.” 
Recently Metcalf (35, p. 222) remarks: “Its origin is 
unknown, but there is some evidence that it was imported from 
the Orient.” Later, in answer to a direct question as to its 
origin, he adds (p. 227): “That is exactly what we would like 
to know more about. The fact that the disease has obviously 
spread from a center leads me to believe that it is an importation 
rather than a disease which has developed here. The fact 
that the locality from which it has spread is the same locality 
into which the Japanese chestnut was first extensively intro- 
duced, that the Japanese and Corean chestnuts are highly 
resistant, and are the only varieties that are at all resistant, all 
suggest the hypothesis that the fungus parasite may have come 
from the Orient. However, the origin of the parasite is not 
a matter of practical importance, unless it could be shown that 
the fungus parasite is developing spontaneously in many locali- 
ties from some native saprophytic form, in which case the 
difficulties of control would be greatly increased.” 
In the preceding, Metcalf brings out four points in favor of 
the Japanese origin of the fungus, as follows: (1) Immunity 
of Japanese and Corean chestnuts; (2) Outbreak of disease 
originally in Long Island, where Japanese chestnuts were first 
imported; (3) Spread of the disease from a single center; 
(4) Possibility of Chester’s Cytospora on Japanese chestnut 
being the blight fungus. Let us take up these four points for 
further consideration. 
(1) The immunity of Japanese chestnut does not necessarily 
mean that this fungus occurred on it in Japan, and when brought 
to America spread to the American chestnut, and, finding it a more 
favorable host, caused, the serious outbreak here, as Metcalf 
suggests. It may merely mean that the Japanese is a more 
hardy species. From the statements of Morris (13, p. 43) we 
take it that this is the case, since it is only the Japanese or Corean 
varieties from the more northern regions that show this resist- 
‘ance. Recently it has been found that the Japanese chestnut 
is highly resistant to the black canker, a serious chestnut disease 
now causing trouble in France. Arguing along Metcalf’s theory, 
one could say that this French fungus was of probable Japanese 
