ENDOTHIA PARASITICA AND RELATED SPECIES. 69 
species of Quercus, chiefly Q. prinus and Q. alba, only one case has 
been. noted in which the fungus assumed a typically parasitic réle. 
The data in this case may be summed up as follows: Four inocula- 
tions were made May 27, 1914, on a small tree of Quercus alba. This 
tree was suppressed, and although when cut down it showed about 
30 annual rings it was only 16 feet high and about 2 inches in diam- 
eter. It was in a moist, shady locality close beside a stream, and in 
spite of its small size was apparently healthy. The inoculations 
were made in the usual way from a culture of Z. parasitica on corn 
meal. On August 1 it was noted that all four inoculations were pro- 
ducing pycnidia, and in at least one case typical fans had been 
developed. On October 15 all four cankers had more than half 
girdled the seedling. No observations were made during the winter, 
but at the time the leaves had reached half the normal size, in the 
spring of 1915, the tree was completely girdled. On July 1 this tree 
presented an appearance closely similar to that of a small chestnut 
tree girdled by E'ndothia parasitica. All the leaves above the point 
of inoculation were dead and remained attached to the branches. 
Below the girdled portion, water sprouts had developed, as has been 
frequently described for chestnut trees affected with Z. parasitica. 
Cultures made from this tree showed the fungus to be typical of 
E. parasitica. Whether this case of parasitism was due to unusual 
virulence on the part of the fungus or to unusual susceptibility on 
the part of the host is, of course, merely a matter of conjecture; the 
latter alternative seems, however, somewhat more probable, as other 
inoculations with this strain of the fungus on Q. prinus and Q. alba 
failed to show similar results. 
In addition to the above, a somewhat similar observation has been 
made by the writers near Amherst, Mass. In connection with other 
work, a sprout of Quercus prinus about an inch in diameter was 
inoculated with Endothia gyrosa on July 15,1914. When this inocu- 
lation was made the tree was partly (about one-fourth) girdled. 
E. gyrosa developed normally and by October 1, 1914, had produced 
several pycnidial stromata. No change was apparent when the inocu- 
lations were examined in May, 1915. 
E. parasitica was abundant in the region, however, and apparently 
gained entrance through the cuts originally made, for when the plat 
was next visited, August 17, 1915, the sprout appeared quite dead, 
though still retaining its full-sized dead leaves. Further examina- 
tion showed numerous pycnidia of Z. parasitica in addition to those 
of Z. gyrosa near the region of the original inoculation. The pycnidia 
of E. parasitica were on all sides of the stem, while those of EL. gyrosa 
were confined to the portion above the cuts made in inoculating. The 
mycelial fans typical of £. parasitica were abundant also. These 
