Vol. 40 96°08 
BULLETIN 
OF THE 
TORREY BOTANICAL CLUB 
ee ee 
. 
APRIL 1913 
Studies in the cytology of the Hymenomycetes, especially the Boleti 
MIcHAEL LEVINE 
(WITH PLATES 4-8) 
The discovery of sexual cell fusions in the rusts has given a 
great impetus to the investigation of the origin of the binucleated 
cells in the Basidiomycetes. It made clear that cell fusions 
without immediate nuclear fusions are possible and may result 
in an undoubted sporophyte with binucleated cells. An added 
importance is also given to the study of the nuclear divisions in 
the basidium as the stage at which chromosome reduction takes 
place. 
Since the appearance of Brefeld’s familiar observations on the 
origin of the carpophore of Coprinus stercorarius, it may be 
regarded as established that no specialized sex organs are necessary 
for the initiation of the development which leads to the formation 
of basidia. Brefeld (1876-77) grew the mycelium of this fungus 
from spores on dung decoction and described and figured two 
methods of carpophore formation without finding any structures 
visibly differentiated as sexual organs. He found that the 
carpophore might have its origin in a single mycelial thread or from 
a sclerotium, depending on the condition of the culture medium. 
Brefeld’s results seemed for a time to settle the question as to the 
existence of any form of sexuality in the Basidiomycetes. The 
question as to the significance of the hyphal fusions in the my- 
celium, however, still remained open. Two types of fusions 
between hyphae in the Basidiomycetes have been long known, 
[The Butietin for March 1913 (40: 97-136. pl. 2) was issued April 7.] 
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