CHAPTER V.—TYPE OF THE ASCOMYCETES AND 
RHODOPHYCE. 
Within recent years our knowledge of the sexual process in certain 
of the higher fungi, the Ascomycetes, has been greatly advanced by 
the classical researches of Harper. These researches have inaugurated 
a sort of renaissance in the study of the sexual process in the fungi; 
for within the last decade the doctrine of sexuality in the Ascomycetes 
as advanced by De Bary has been strenuously denied in some 
quarters, especially among the mycologists of the Brefeldian school, 
and the view that no sexual reproduction at all occurs in this group 
had gained considerable ground. 
Harper’s work upon certain Per/sporeacee and Discomycetes leave 
no doubt concerning the true sexual process in those groups, and it is 
reasonable to expect that further research will bring to light the 
presence of sexual reproduction in other genera in which the existence 
of sexuality seems far more questionable. 
In the development of the sexual organs and in the behavior of the 
egg-cell, there is represented here a type of sexual reproduction very 
different from that known in other fungi and in the green alge. The 
closest parallel is found in the Rhodophycee and in certain lichens. 
There is certainly a striking and suggestive resemblance between the 
structure of the sexual organs and the process of development subse- 
quent to fecundation in Spherotheca, Pyronema and Collema on the 
one hand, and in such forms of the red alge as Batrachospermum 
and Nemalion on the other. It ig not improbable that further research 
will reveal a tolerably well connected series from forms like Sphero- 
theca to the remarkably complex Dudresnya, and we may accept 
without much reserve the view that the great groups to which these 
representatives belong represent related phylogenetic series. In this 
chapter, therefore, I shall present the sexual process in Spherotheca, 
Pyronema, Collema, Batrachospermum and Dudresnya as repre- 
sentative of the type of sexuality in the Ascomycetes, including that 
form in lichens, and in the Floridez. 
What follows concerning Spherotheca and Pyronema is based 
exclusively upon the studies of Harper (’95, "96, 1900). 
SPH ZROTHECA. 
Both antheridia and oégonia of Spherotheca arise as lateral branches 
of neighboring mycelial filaments, the development of the oégonium 
