ENDOTHIA CANKER OF CHESTNUT 
P. J. ANDERSON AND W. H. Rankin! 
(Received for publication March 27, 1914) 
HOSTS 
, The Endothia canker was first discovered by Merkel (1906), on the 
American chestnut (Castanea dentata), in the New York Zoological Park 
during the summer of 1904. Metcalf (1908 a) states: ‘‘ Observations 
made by the writer during the past year indicate that all varieties and 
species of the genus Castanea are subject to the disease except the Japanese 
varieties (Castanea crenata Sieb. and Zucc.).’”” In the same year Metcalf 
(1908 b) states that the Japanese varieties are in general resistant, and 
Murrill (1908 a:27) reports having found the canker on a Japanese chest- 
nut and on the chinquapin (Castanea pumila) in the New York Botanical 
Gardens. Pantanelli (1911), Metcalf (1912 b:76), and Morris (Clinton 
1911:725) give evidence that varieties of the European chestnut (Cas- 
tanea sativa) are also subject to this disease. Morris (Clinton 1913:376) 
gives his observations on orchard varieties as follows: Corean, Chinese, 
and northern Japanese varieties were not attacked, although they had 
grown for five years alongside diseased trees, while’ southern Japanese 
varieties were attacked; but the Corean, Chinese, and northern Japanese 
varieties were attacked after having been grafted on American stocks. 
A small number of the eastern and the western chinquapins were unaffected 
except for one branch of a single tree. Many points that are essential 
for determining the real value of these observations as establishing the 
immunity or the susceptibility of these varieties are unfortunately not 
given. Fairchild (1913) reports having found the disease in northern 
China on a species of Castanea, probably C. mollissima. 
Van Fleet (1914) records many observations concerning the spread 
of the canker in the breeding-plots at Washington, D. C., where he has 
been breeding chestnuts experimentally since 1894. Nearly all.the trees 
having C. americana in any combination have disappeared. Recently 
Van Fleet has worked with selections made from self- and chance-pol- 
linated individuals of the chinquapin and Asiatic types. He has obtained 
many precocious hybrids from these crosses. He reports his observations 
on the resistance to the canker shown by these hybrids as follows: 
“Seedlings of Paragon chestnut, the best variety of the European 
type, pollinated with our native species, attained an average height of 
1 Names of authors arranged alphabetically. 
533 
