204 SEMI-CENTENNIAL OF TORREY BOTANICAL CLUB 
surface, using a loop needle and sometimes slightly rubbing the 
surface of the hymenium with the loop. Some of the material 
was then transferred to a drop of sterile water on a sterilized slide. 
Poured plate cultures were made in the usual way, being inocu- 
lated directly from the drop prepared on the slide, using prune- 
juice agar and Shear's cornmeal agar. Before making the poured 
plates, the drop used for inoculation was carefully inspected with 
the 16 mm. objective and no Botrytis spores were seen in it, in fact 
no spores were observed except those of the Sclerotinia. 
After about twenty hours the agar plates were inverted and a 
number of germinating spores were marked. Only the colonies 
of mycelium clearly arising from one spore and well separated 
were marked. While the original spore had become considerably 
swollen and not recognizable with absolute certainty in some cases, 
it appeared from the figure of the mycelium that the Sclerotinia 
spore had given rise to the growth in every case marked. Later 
in the same day five of these colonies were transferred to slant 
tubes of prune agar. The following day six more plantings were 
made from separate colonies growing from marked single asco- 
pores. By this time the colonies had become very complex and 
were plainly visible. Three days from the making of the poured 
plates the colonies were confluent and vigorous and the charac- 
teristic Botrytis spores had commenced to be formed. Apparently 
all of the colonies originating from the ascospores gave rise to the 
Botrytis spores and there were no contaminations, all of the colonies 
being of the same sort. 
Of the single-spore transfers to prune-juice agar, three of 
those made on the first day failed to grow, presumably the young 
mycelium had been caught on the needle used in the transfer, 
since some had not been found on the slant after making the trans- 
fer. The remaining eight single-spore cultures developed very 
uniformly and all produced abundant Botrytis spores. 
On June 24, plantings were made from each of the eight pure 
cultures on prune-agar slants to sterilized geranium rootstocks and 
to sterilized potato plugs. On the potato plugs the growth was 
identical with that originally secured from crude plantings of the 
spores of Botrytis and Sclerotinia. After four days, Botrytis 
spores could be seen with a lens in nearly all of the cultures and 
