364 CONNECTICUT EXPERIMENT STATION REPORT, IQI2. 
The Andersons (1) were among the last to study the rela- 
tionship of Diaporthe parasitica to the genus Endothia. Their 
studies having led them to believe that the blight fungus, 
though related, was entirely distinct from Endothia gyrosa, they 
have placed it under Endothia as E. parasitica (Murr.) Anders. 
Although the writer started out to prove the identity of the 
chestnut blight with the Endothia gyrosa of Europe, he has 
been forced to conclude from his microscopical, cultural and 
inoculation studies that it is not exactly identical with that 
species, as is held by von Hohnel and others. The relation- 
ship, however, is so close that he cannot, on the other hand, 
agree with the Andersons in considering it an entirely distinct 
species. Hence he (9) has placed it as a variety under that 
species, calling it Endothia gyrosa var. parasitica (Murr.) 
Clint. 
The preponderance of opinion of those who have made a 
critical study of the fungus,. therefore, is that it is not an 
entirely new species, but that it is merely a strain, or at most, 
a variety of a previously described saprophytic or semi-parasitic 
species, that for certain reasons has now attained unusual viru- 
lence in the northeastern United States. 
CHARACTERISTICS OF THE DISEASE. 7 
As to the Host. It is easy enough to distinguish this disease 
on the smooth bark of sprouts or young trees, Plate XXIII a, 
since it forms definite cankers by killing the infected bark, 
and these usually increase in size until the entire stem or limb 
is girdled. These cankered spots are slightly sunken, and 
distinguished from the healthy bark by a chestnut-brown color, 
whereas the normal bark is more of a greenish-brown. Often 
the bark on these cankered spots is more or less cracked, and 
in time the fruiting pustules show as numerous minute cushions 
projecting through lenticel-like openings. 
On the rough bark of the older trees the cankers do not 
show very distinctly, though when cut out, as shown in Plate 
XXIII b, they give a cankered effect. Frequently with these 
the whole bark becomes infested, and the presence of the 
fungus is shown by the fruiting pustules breaking out from 
the deep cracks of the bark. Often when these do not develop, 
