TAKEWO HEMMI 289 
requires four or five days. From these facts, we infer that infection by the 
pyenospores can occur only in the warm period of summer. 
The process of germination begins with an enormous swelling of the 
spores, especially in width. The spores measuring 5.25-1 2.25 x 1.75-2.63// 
before germination were found, at the end of twenty-four hours in a bark 
decoction, to measure 6.13-14.0 x 4.72-7.0//; and not infrequently they 
reached 1 5.75 x 7.88 fi just before germination. In such cases, the spores 
took various irregular forms, — ellipsoid, ovoid, obovoid, subglobular, etc. In 
a few cases I noticed that some spores were divided into two cells just before 
germination (PI. X, Fig. 4-5.). The spores germinate in thirty to sixty hours, 
throwing out one to three germ-tubes. Usually a germ tube grows out from 
one end, and this is followed later by a second one from the opposite end (PI. 
X, Fig. 5-7.). The germinating hyphae are at first hyaline, about 3.2-4.0 ju in 
width and occasionally swollen in an irregular shape. The branching and 
septation of the germ tube or mycelium then take place; and the old hyphae 
often turn gradually to a yellow or light brown color after three or four days. 
The germinating spores and hyphae are at first granular in contents and after 
a while vacuolization occurs in many cases. 
In the experiments described above, I took all the spores from pure 
cultures. Such swelling and manner of germination of the pyenospore are 
not infrequent in many genera belonging to the Ascomycetes. Adekhold 
(1903) 0 also described the same process in the case of Valsa leucostoma 
(Peks.) Fr.; but such two-celled spores have not been observed by him. 
According to De Bary (1887) S) , the cause of such enormous swelling of the 
spores before germination is attributed to absorption of water. On the con- 
trary, Anderson and Rankin (igi4)-^ speaking about the phenomenon in the 
case of Endothia parasitica (Murr.) Anders., the chestnut blight fungus, 
write : — "The swelling of the spores is due, not merely to a mechanical 
imbibition of water, but also to a process of growth. Pyenospores stained 
just before the germ tube is started show that the increase in size is accompa- 
nied by active nuclear division, two to six nuclei then being present. The 
