FUNGI OF IMPORTANCE IN THE DECAY OF TIMBERS. 37 
Attempts were next made to dislodge oidia from agar-plate cul- 
tures by air currents from an electric blower delivering 1.4 cubic feet 
per minute. The apparatus was so set up that at least a part of the 
oiclia removed would lodge on sterile agar plates. From cultures 
with a very heavy development of oidia, a very few were dislodged, 
as determined by microscopic examination of the surface of the 
sterile agar plates and subsequent growth. An electric fan making 
a much stronger current of air removed larger, though not consider- 
able, numbers of oidia. Oidia on wood blocks from cultures were not 
removed any more readily, inasmuch as they are formed only in 
moist atmospheres and are. themselves moist and sticky. The same 
procedure was tried with other species showing secondary spores in 
culture. Individual oidia or small clusters were likewise dislodged 
from agar cultures of CollyMa velutipes. The stronger current of 
air removed a few of the chlamydospores of Forties officinalis, but 
oidia could not be removed from cultures of Coniophora cerebella 
or Merulius lacrymans or chlamydospores from cultures of Trametes 
rooiniophila or Forties igniarms. It is thus seen that secondary 
spores of most of the species mentioned do not appear to be adapted 
to dissemination by wind. 
Oidia are readily removed by contact. Prints can be made upon 
glass slides or cover slips by simply allowing the glass to touch the 
surface of a culture. More sticky substances like agar retain more 
oidia than glass. The obvious application of these facts is insect 
dissemination, for insects with sticky feet and hairy or bristly ap- 
pendages should be able to remove and carry away large numbers of 
the moist oidia. A cockroach caught in the laboratory was placed 
upon agar cultures of Lenzites sepiaria for a few minutes. Exami- 
nation of the roach's appendages under the microscope disclosed 
large clumps of the oidia stuck to the tarsi. Another roach placed 
upon an agar culture was transferred to a sterile agar plate, allowed 
to remain a few seconds, and then the plate was incubated. In three 
days the plate showed a winding growth of Lenzites sepiaria and 
contaminations, chiefly Penicillium, presumably where the roach had 
walked over the agar during his captivity. A cockroach was then 
placed in a flask containing a wood-block culture of Letizites sepiaria 
and examined after a few minutes. A few oidia were found upon 
the pads of the tarsi and on the bristles of the leg's and antenna? (PL 
VIII, fig. 3). 
Water will dislodge large quantities of oidia from agar or wood 
cultures. Sterile water dropped from a pipette upon the inoculum 
of a new transfer will carry or splash large numbers of oidia - on the 
surrounding sterile agar. 
From the above results it is concluded that oidia occurring either 
on wood or agar are moist, sticky spores, not adapted to air dissemi- 
