219 
the A scocarp in Monascus. 
there fuse in pairs with female nuclei as in Pyronema . Probably 
also there is an excess of female nuclei in the ascogonium, 
which remain unfertilized and eventually degenerate. The 
nuclei which remain in the terminal cell after the cutting off 
of the central cell can certainly be regarded in this light, and 
perhaps, too, some of the nuclei enclosed in the central cell come 
under this heading. Stevens has shown that in Albugo Bliti 
(20) and Alfoigo Portulacae (21) numerous male nuclei pass 
into the oogonium and fuse in pairs with female nuclei, while 
other nuclei of the oogonium remain unfertilized in the 
periplasm. 
It is therefore necessary to examine more closely the details 
of these various features to determine, if possible, whether it 
is merely a case of parallel behaviour or whether a definite 
relationship is indicated. 
The members of the Oomycetes which show a marked 
alternation of generations by the formation of a promycelium, 
e. g. Phytophthora omnivor a, De Bary, and Pythium proliferum 
(6), are those which approach most nearly the simple sexual 
Ascomycetous type, of which Monascus is an example. In the 
above parallel the ascus of the latter is equivalent to the 
zoosporangium of the sporophyte generations of Phytophthora 
and Pythium. From a type similar to these forms the 
Ascomycetous type represented by Monascus could be derived 
by the suppression of the differentiated oospore stages and the 
transference of its hibernating function to the zoosporangia of 
the sporophyte, these structures becoming much more definite, 
owing to the acquirement of that function, and producing only 
a small limited number of resistant spores. Among the 
difficulties standing in the way of the acceptance of this hypo- 
thesis are the difference of the mycelium in the two instances, 
the lack of differentiation of the zoosporangia of the sporophyte 
from those of the gametophyte, the different methods of spore- 
formation in sporangia and asci, and the lack of intermediate 
forms. 
Considering these in turn, the difference of the mycelia 
consists in the absence of septa, except in the reproductive 
