May 1906] Peridermium Cerebrum Peck , Etc. 
91 
close proximity to the oak, and we have never seen it on any host 
in such great abundance as it was on these two plants. The sori 
were not quite so numerous and well developed on the Q. Prinus 
as on Q. Marylandica, which is a normal and common host of the 
fungus. 
Shirai 4 has, according to Klebahn 5 , proven by successful in¬ 
oculation of seedling oaks ( Quercus serrata, Q. variabilis and Q. 
glandulifera) the connection between Cronartium gigantium 
(Mayr) Tubeuf and what he calls Cronartium Quercuum 
(Cooke) Miyabe. Whether this Cronartium, which occurs on the 
oaks in Japan, is identical with the plant occurring on our oaks we 
are unable to say, not having had an opportunity to examine 
Japanese specimens. The authority given by Tubeuf for Cro¬ 
nartium Quercuum is also (Cooke) Miyabe. 
The American plant was first described, so far as we can 
learn, by Berkeley 6 in 1874 as Cronartium Asclepiadeum Quer¬ 
cuum, collected on Quercus nigra in South Carolina and on Q. 
velutina in Pennsylvania. We find no description of the plant by 
Cooke. 
In regard to Peridermium gigantium (Mayr) Tubeuf, this 
w r as first described or mentioned at least by H. Mayr as 
Aecidium gigantium and transferred to Peridermium by Tubuef 7 . 
It is reported as occurring on Pinus desiora, P. Thunbergi, 
P. parvidora and P. Linckuensis in Japan. We had an oppor¬ 
tunity during the past summer, through the kindness of Prof. 
Tubeuf, to examine the Japanese specimens of this fungus upon 
which his figures of the plant are based and which are preserved 
in the collection of the Forestry Institute at Munich. The speci¬ 
mens are identical in appearance with those collected on Pinus 
Virginiana in the vicinity of Washington. Moreover, the sweet 
sap containing spermatia, which is said to exude from the surface 
of the swellings produced by the fungus in Japan, is equally char¬ 
acteristic of our plant. We are, therefore, of the opinion that 
Peridermium gigantium (Mayr) Tubeuf is the same as P. cere¬ 
brum Peck, which was described many years before the Japanese 
plant. Though the matter can not be regarded as settled, all the 
evidence at hand at present points to the idenity of these plants 
and their genetic connection with the uredo and teleutospore 
stages which occur on various species of oak and which are 
known as Cronartium Quercuum. 
It may be interesting to add a list of species of pine and oak 
upon which the two forms have been found in this country. 
4 1. c. 
5 Die Wirtswechselnden Rostpilse, 1904, p. 381. 
8 Grevillea, 1874, 3, 59. 
7 Pflanzenkrankheiten durch Kryptogame Parasiten verursacht, 1895, 
p. 429. 
