36 BULLETIN 1053. U. S. DEPARTMENT OF AGRICULTURE. 
The chlamydospores of Trametes serialls proved no more resist- 
ant. It is possible, however, that the conditions under which they 
were formed (in a moist medium) and their previous wetting in 
obtaining them may render them more sensitive to drying. 
ALTERNATE WETTING AND DRYING. 
The oidia of Lenzites sepiaria and L. trabea do not survive alter- 
nate wetting and drying. Oidia were removed in quantities from 
an agar plate culture to glass slides. Two slides were retained as 
checks and the oidia on two others were wet with sterile distilled water 
and immediately put away until dry. One slide was allowed to dry 
under room conditions, while the other was dried in the presence of 
calcium chlorid. Germination tests were then made. After 16 hours 
the controls showed practically perfect gennination. while of the wet 
and dried oidia three Van Tieghem cells showed less than 1 per cent 
and one 5 per cent germination. Kepetitions of the test gave similar 
results. 
EXPERIMENTS UPON THE DISSEMINATION OF THE OIDIA OF 
LENZITES SEPIARIA. 
Flask cultures of Lenzites sepiaria and L. trabea obtain a much 
better start than cultures of the other fungi, because of the oidia. 
The water in the tube containing the bean-pod cultures used as 
inoculum becomes a suspension of oidia. and these are distributed 
all over the flask to start centers of growth, whereas cultures of 
fungi possessing no oidia can only be spread from the inoculum 
and consume about one month in covering all the blocks in the 
flask. In the light of these facts a few experiments were carried 
out with a view to ascertaining by what means and how easily 
the oidia of this fungus might aid in dissemination. It is realized 
that any points made here are contingent for their importance 
upon the question as to whether or not the oidia occur naturally. 
Inasmuch as Falck (13, p. 319) doubted whether wind would be 
of any importance in disseminating oidia, the writer set out to de- 
termine how easily the oidia might be removed from plate cul- 
tures. A new transfer was inverted over a sterile agar plate, sealed 
with gummed paper, and set away in the incubator. In the first 
test with L. sepiaria, an abundance of oidia were found upon the 
sterile agar plate after a week. Eepetitions gave inconsistent re- 
sults, but it was shown that small numbers of oidia may be released 
during their formation. Shaking a plate culture over a sterile agar 
plate yielded results similar to those reported by Falck (15, p. 144). 
Oidia were dislodged in some cases, but not in all. The same test 
was tried with Collybw velutlpes, and pure cultures were obtained 
from oidia shaken off. 
