420 BOTANICAL GAZETTE [NOVEMBER 
and always small. It is noted that the conidial tufts of the former 
often grow together, exhibiting a smooth upper surface. This 
does not occur with the latter species. 
4. S. fructigena occurs on pome fruits, while S. cinerea occurs 
on stone fruits. 
5. The ascospores of S. fructigena are sharply pointed at the 
ends, while those of S. cinerea are rounded on the ends. The former 
are without oil droplets, the latter possess them. 
Observations 
Our observations in this study are limited to behavior on fruit 
and in pure culture, size of conidia, and size of asci and ascospores. 
No apothecia could be obtained from Europe; however, the 
measurements made by ADERHOLD and RUHLAND were available. 
In the beginning, letters requesting pure cultures or mummied 
fruits bearing both species were sent to different parts of Europe. 
Pure cultures of S. cinerea and S. fructigena were twice sent me by 
Dr. J. WesTERDIJK of the Association internationale des botanistes, 
Bureau pour la distribution de cultures de moisissures, Amsterdam. 
Mummied fruits bearing S. fructigena were sent me by the following 
persons: Dr. Lurcr MonTEMARTINI of the University of Pavia: 
Professor Dr. C. WrEHMER of Hannover; Professor Dr. PAUL 
SORAUER of Berlin; Gy pre IstvANFFI of Budapest; and Professor 
Dr. G. Lustner of Geisenheim. Similar fruits were also obtained 
from the government experiment stations at Geisenheim and 
Dahlem. TI also received a box of mummied fruits from the Depart- 
ment of Agriculture of New South Wales. : 
Among the fruits sent me by Dr. LustNER were some mummied 
plums bearing Sclerotinia cinerea. Its outward appearance was 
so strikingly different from that of S. fructigena that its recognition 
was a matter of first glance. Both species were easily isolated on 
other fruits and then in pure cultures. This plan gave an ony 
and practical method of observing the forms as they grew side 
by side, many times on the same pear or apple and oftentimes ™ 
the same petri dish. 
BEHAVIOR ON FRUIT—Quinces taken from the same tree, and 
subjected to the same external conditions, were inoculated with 
