260 BOTANICAL GAZETTE foctons 
tions among the red algae in the trichogyne nucleus of Batrachosper- 
mum and its binucleate sperms (SCHMIDLE 99) of conditions which if 
found more generally may assist to a clearer understanding of these 
remarkable fungal groups and materially support THAXTER’s view. 
It is very difficult to conceive a relationship : between the sexual 
organs of the simpler Ascomycetes (Gymnoascales, etc.) and those of 
the lichens and Laboulbeniaceae. One can scarcely conceive of a pr 
cess of simplification by which the former could have come from the 
latter. On the other hand, the general principles of sexual evolution 
operating upon the simple sexual organs of the lower Ascomycetes 
would be more likely to result in the conditions illustrated by Monastts 
Pyronema, and Sphaerotheca than those of the lichens and Laboulber- 
laceae. Such an evolution would also be in sympathy with the general 
- ascending complexity of vegetative thallus and ascocarps in the forms 
under consideration. This view would place the progenitors of the 
simpler Ascomycetes in a region much lower than the Rhodophycett, 
and perhaps relate them to certain Phycomycetes. There is of course 
the possibility of the Ascomycetes being polyphyletic, removing the 
Laboulbeniaceae from the general assemblage, which might 
of these difficulties, but we must know much more pee! 
comparative development of the ascocarps in the groups before 
a view can be considered well-founded. sey 
The author cannot agree with any view that fixes the ee 
Mucorales and Ascomycetes from conditions illustrated by any 
living form. The problems of relationship involve so many Oe 
. , in Set, 
tions, those of taxonomy as well as evolutionary pam 
that arrangements of living types in series seems futile. ve in 
that the most hopeful line of speculation will be founded - foros 
study of the principles of sexual evolution and a comparison 0! 108 
in this light, with such checks as may be furnished by the — 
morphology of all phases in the life history of the oR al orgats 
principles indicate to the author much simpler primitive sexu 
for the Ascomycetes and Mucorales than have been Sup 4 pert 
with their origin below the Peronosporales (Oomycetes); e honales 
finally, for the Mucorales at least, from the isogamous 43 
(Davis ’o3, Pp. 335). cae 
€ cannot at this stage in the progress of investigations . 
