180 DopGE: RELATIONSHIPS OF FLORIDEAE AND ASCOMYCETES 
In certain species of Lachnea, as noted above, the hymenium is at no 
time enclosed by the peridium. All these observations are quite 
contrary to the views that have been commonly held. The signifi- 
cance of the rather delicate weft of hyphae covering the hymenium 
of Geoglossum, Mitrula, Spathularia, Microglossum, Cudonia, etc., 
according to Dittrich and Durand, can not be regarded as entirely 
clear and the question whether the ascocarps in these cases are 
cleistocarpous at first can only be settled by further study of 
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Fic. 7. Apothecium of the Collemas showing the difference between the trichoe 
gynes of C. microphyllum and those of C. pulposum. The trichogyne,, fr, of Cc. 
microphyllum, represented by dotted lines, is perpendicular to the surface of the 
thallus; the trichogyne, tr’, of C. pulposum, also represented by dotted lines, lies 
more or less horizontally in the thallus. The figure shows that paraphyses arise 
from the vegetative hyphae, v.hy, as well as from the stalk, stk, of the ascogonium 
and that ascogenous hyphae, a.hy, arise from several cells of the ascogonium which 
are connected by broad pores in the cross walls. a.c, ascogenous cells; @s¢, ascus; 
exc, excipulum; n, Nostoc colonies; spm, spermatia; stk, stalk of ascogonium. After 
Stahl, Bachmann, and others. 
earlier stages. The real question as to whether an ascocarp is tO 
be classed as open or closed in its early stages depends on whether 
the young hymenial layer arises endogenously as in Ascobolus 
furfuraceus (F1G. 9, B), or is from the first free and exposed as in 
Pyronema (Fic. 11, B). : 
Authors have commonly recognized at least four types of 
