20908 BOTANICAL GAZETTE [OCTOBER 
WELLsrorD (15), and Fraser and Brooks (16). This is in 
harmony with the view that there is no fusion in the ascogonium.. 
SEXUALITY 
It is unnecessary to review here the history of our knowledge 
of the sexuality of the Ascomycetes, as this has been thoroughly 
done quite recently by HARPER (22, 23), OVERTON (31), and 
Lotsy (26); while the latest literature has been discussed by 
FRASER (16). The passage of the nuclei from the antheridium into 
the ascogonium of Pyronema confluens, as reported by HARPER 
(22) and confirmed by CLaussEN (8), would seem to have estab- 
lished the view that the antheridium and ascogonium are to be 
regarded as sexual organs, even though the antheridium may be 
functionless or lacking in other cases. DANGEARD’S (10) failure 
to find a passage of nuclei from the antheridium into the ascogonium 
of Pyronema confluens may be due, as BLACKMAN and FRASER (3) 
suggest, to his having worked on a different form from that observed 
y Harper and Ciaussen. The writer has found that the 
antheridia may behave differently in different strains of Pyronema 
confluens. In one (BROWN 5), the antheridia never fused with the 
trichogyne, while in a strain of Pyronema (confluens) omphalodes, 
obtained through the kindness of Dr. F. J. SEAVER, the antheridium 
at the proper stage, as has been figured by him (SEAVER 34), can 
be readily seen fused to the trichogyne. The two strains, more- 
over, show differences in the conditions under which they can be 
grown. It is interesting in this connection that VAN TIEGHEM 
(35) has shown that under cultural conditions the antheridium of 
Pyronema confluens may be normal, rudimentary, or absent, while 
the ascogonium develops normally. 
Since recent work has shown that the fusion of nuclei is the 
essential part of fertilization, the discussion of the sexuality of the 
Ascomycetes has naturally centered around the nuclear fusions. 
In the simple forms Eremascus fertilis, Endomyces magnusit 
(GuiLttieERMoND 18), and Dipodascus albidus (JuEL 24), the 
antheridium and oogonium fuse and give rise at once to a 
single ascus. In Eremascus fertilis the antheridium and oogonium 
are uninucleate, and in all three cases the primary nucleus of the 
