The Biology of Polyporus Pargamenus Fries 71 
It is remarkable that such minutely microscopic plant 
structures as these fungous spores should retain their vitality, 
germinate, and develop into infectious plants after being 
kept for ten months in the state of extreme dessication 
afforded by their storage in a warm room. That these results 
are not out of accord with the vitality of the spores of other 
wood-destroying fungi are shown by the experiments of 
Falek. Falck aC 1909 ) succeeded in germinating spores of 
species of Lenzites, some of which had been preserved in a 
state of dessication on glass slides for one year and nine 
months. He found that in general the spores of Lenzites 
species retained their vitality longest when they were col- 
lected in thick layers on dry glass slides and carefully pre- 
served dry. When the spores beeame wet by the moisture 
expelled from the fruit-bodies in the process of shedding, 
Falck found that they stuck together and died in a propor- 
tionately shorter time. If the waxed paper containing the 
shed spores of Polyporus pargamenus had been stored in 
some cool place or out of doors it is quite likely that they 
would have retained their vitality for a considerably longer 
period than when stored in a warm room. Under natural 
conditions it stands to reason that the shed spores may be 
blown hither and thither for weeks and months without los- 
ing their vitality. As a result of their ability to retain their 
vitality after being subjected to dessication for long periods, 
their chances for becoming lodged in favorable situations are 
greatly enhanced. 
CHARACTERISTICS OF THE MycreLIumM In PuRE CULTURES. 
Culture Methods.—The basidiospore was employed as the 
source for most of the cultures used in the present investiga- 
tion. Owing to the thin leathery nature of the sporophores, 
they are not well adapted to the making of pure cultures by 
the tissue method. Furthermore, in securing pure cultures 
from very thin, leathery sporophores one is almost obliged 
to use the spore method since it is usually very dificult to 
obtain pieces of uncontaminated tissue from such thin sporo- 
phores. In addition it was found to be very difticult to 
