188 DopcE: RELATIONSHIPS OF FLORIDEAE AND ASCOMYCETES 
traced back to the ascogenous cell. There is at this time (FIG. 
11, A) no perithecial layer such as is to be found in A. furfuraceus 
at such a stage. The outer hyphae are now becoming more com- 
pact and some of them begin to grow inward forming what in 
appearance is an inrolled margin, covering in part the hymenial 
layer which as I have stated is visible from the first and remains 
exposed throughout the development. The narrowness of the 
opening above the hymenium at this time led me to erroneously 
describe the young fruit as “‘at first closed, then opening by a 
pore” (36). Microtome sections and careful examination of 
large numbers of specimens grown on the surface of agar media in 
plate cultures have made it clear that the hymenium is never closed 
over; in fact the ascogonium is not more “protected” than are 
KX 
Re del! 
RU ETIN cb 
SS ES 
; oN 
. 11. Gymnocarps. A. Ascobolus magnificus; B. Pyronema confluens. a.6, 
ascogenous cell; a.ky, ascogenous hyphae; am, antheridium; oog, odgonium; ud 
paraphyses; ‘stk, stalk; ir, trichogyne; A, original; B, Harper. 
p 
. Zs 
the ascogonia of Pyronema. Sections of older apothecia show that 
there is a well-developed sterile margin, the ‘‘excipulum,” the 
outer cells of which strongly refract the light thus making 4 
beautiful snow white margin which is inrolled at first (FIG. 12) 
but later as the hymenium broadens becomes expanded or even 
reflexed (FIG. 13). 
The second type of apothecium which is at first closed and 
later opens is illustrated by the familiar figures of Ascobolus 
furfuraceus. Not only is the ascogonium entirely enclosed at an 
early stage but the young hymenial layer is completely covered by 
