274 ON ' A NEW CANKER-DISEASE OF PRUNUS YEDOENSIS, etc. 
this medium. 
When the spores are inoculated on the central portion of the same medium 
in Petri-dishes or Erlenmeyer's flasks, the creeping mycelium spreads radially 
toward the marginal portion of the medium, and the color of the mycelium is 
also brown. This character is one of the marks which can be used in dis- 
tinguishing the present fungus from other species of Valsa. The fungus, 
isolated from Prunns yedoensis, grows on both bark-decoction agar of Prunus 
yedoensis and Prunus Mume with the undistinguishable characters; and the 
fungus, isolated from Prunus Mume, indicates the same characters. This fact 
may prove that those two fungi belong to one species. But I had no oppor- 
tunity to make a culture of the fungi isolated from other host plants on the 
same medium. 
(3) Apple-Fruit Slice. 
On this medium, the white mycelial growth of the causal fungus is at 
first very active, but soon it turns grayish yellow or yellow. On the same 
medium Valsa Mali also grows actively, but the mycelium is white or gray 
in color and the substratum gradually turns black; while in the case of our 
fungus the color of the substratum remains unchanged. 
Up to the present time, neither kind of spores and stromata of trie fungus 
is produced on this medium, while Valsa Mali produced them on some of 
the same cultures. 
(4) Fruit-Juice Agar. 
I used apple, apricot or pear to make this culture ; and the cultural 
characters are, on the whole, similar in all cases. The mycelial growth was 
most vigorous and rapid. The color of the mycelium showed also a common 
characteristic on these media. Cultures containing agar showed at first a 
white cottony mycelial growth, but it gradually turns yellow or greenish 
yellow, while in Valsa Mali the mycelium retains for a long time its white 
color, and in Valsa Paulowniae it gradually turns from snow white to light 
