436 CONNECTICUT EXPERIMENT STATION REPORT, IQI2. 
the wounds inoculated with E. gyrosa, sometimes this injured 
bark was a little more extensive than with the checks, which 
indicated a slight but futile attempt at parasitism. Occasionally, 
on this dead bark and exposed wood, a slight fruiting growth 
of the fungus as a saprophyte was formed. 
With var. parasitica, however, the bark was gradually killed 
in an increasing area surrounding the point of inoculation, and 
this had a more or less irregular outline, spreading faster in 
some directions than in others. Eventually the whole stem or 
limb was encircled, if the inoculation was made early in the 
season (see Plate XXVa). At the inoculation point a callus of 
young tissue often developed, and the vitality of this was greater 
than that of the older tissues, since it often remained healthy, 
until, being entirely surrounded by dead tissues, it died as much 
from adverse nutritive conditions as from the direct action of 
the fungus (Plate XXVb). 
After the cankers attained some size, their reddish dead 
bark often became cracked, and the Cytospora fruiting stage 
appeared in more or less abundance. An examination of the 
inoculations as late as the last of December, however, failed 
to show that the asco-stage had developed on any of them. 
Whether this means that ordinarily the mature fruiting stage 
does not appear until the second season, we do not know, but 
it shows that sometimes this is the case. The inoculations made 
early in May on the chestnut sprouts one to two inches in 
diameter entirely girdled these for six to eight inches, forming 
very evident cankers, but not always with a conspicuous develop- 
ment of conidial spores. 
Hosts Inoculated. In the inoculation tests we used seedlings 
and sprouts of both chestnuts and oaks. Considering first only 
the chestnut hosts, we found that, as a rule, the variety para- 
sitica could be more easily inoculated into the sprouts than into 
the seedlings, and that on the sprouts the blight made a larger 
growth in the same length of time. This greater development 
might in part be due to the larger size of the sprouts, which 
varied from about one-half to one and one-half inches in 
diameter, while the seedlings were only about one-quarter to 
three-quarters of an inch in diameter. Out of a total of 177 
inoculations with cultures originally from chestnut made on 
chestnut seedlings, 91, or 51 per cent., took, as compared with 
