184 DopGE: RELATIONSHIPS OF FLORIDEAE AND ASCOMYCETES 
ascogonium is present and that these primordia are completely 
surrounded by a closely packed layer of enveloping hyphae (Fic. 
8, B), but this does not at all settle the question as to how the 
ostiole originates or even whether the hymenium is endogenous 
in its origin. Miss Nichols says that the ascogonium of Cerato- 
stoma gives rise by cell division to a mass of cells from which asci 
finally develop, and that the ostiole results from the schizogenetic 
rupture of the wall at the papillate apex. The interesting account 
of the development of the ostiole in the region of the base of the 
archicarp as given by Kihlman for Melanospora needs confirma- 
tion. According to this account the opening of the ascocarp is at 
a point which in all other cases is at the center of its base. 
Pi ~~ 
i 
i 
Hh 
la 
“ay 
5} Ca 
coast 
y 
Sy 
ie 
{7 
oe 
Soa 
CY = San 
ee. 
ome 
A 
ote 
ry @, 
es 
< 
an OSe. 
\\ 
Fic. 9. Discocarps of Ascobolus. A. Ascobolus Winteri; B. A. furfuraceus. 
a.c, ascogenous cell; asg, ascogonium; a.hy, ascogenous hyphae; exc, excipulum; 
hym, hymenium; pdm, periderm. A, original; B, adapted from Sachs. 
Two types of apothecia have also been commonly recognized. 
First, those like Pyronema (Fic. 11, B), in which the hymenium is 
exposed from the beginning; and second, those like Ascobolus fur- 
furaceus, in which the hymenium originates endogenously and later 
becomes exposed by the bursting of the apothecial envelope (FIG. 9 
B). The method of the development of the apothecium of Pyronema 
as representing the first type is certainly well known. No excipu" 
lum is formed and the paraphyses and asci form a uniformly supet- 
ficial naked layer (Fic. 11, B). Ascodesmis nigricans is an even 
more simple and open type of fruit body. The apothecium of 
