THALLOPHYTES : FUNGI 
275 
a little sphere, which suggested the name Microsplicera 
(Fig. 241). The heavy wall of the ascocarp bears beauti- 
ful branching hair-like appendages (Fig. 242). 
Bursting the wall of this spore fruit several very delicate, 
bladder-like sacs are extruded, and through the transparent 
wall of each sac there may 
be seen several spores (Fig. 
242). The ascocarp, there- 
fore, is a spore case, just as 
is the cystocarp of the Red 
Algae ( 174). The delicate 
sacs within are the asci, a 
word meaning " sacs," and 
each ascus is evidently a 
mother cell within which 
asexual spores are formed. 
These spores are distin- 
guished from other asexual 
spores by the name asco- 
spore. 
It is these peculiar moth- 
er cells, or asci, which give 
name to the group, and an Ascomycete, Ascus-fungus, or 
Sac-fungus, is one which produces spores in asci ; and an 
ascocarp is a spore case which contains asci. 
In the mildews, therefore, there are two kinds of asexual 
spores : (1 ) conidia, formed from a hyphal branch by abstric- 
tion, by which the mycelium may spread rapidly ; and (2) 
ascospores, formed in a mother cell and protected by a heavy 
case, so that they may bridge over unfavorable conditions, 
and may germinate when liberated and form new mycelia. 
The resting stage is not a zygote or an oospore, as in the 
Algae and Phycomycetes, no sexual spore probably being 
formed, but a heavy-walled ascocarp. 
185. Other forms, The mildews have been selected as a 
simple illustration of Ascomycetes, but the group is a very 
FIG. 242. Ascocarp of the lilac mildew, 
showing branching appendages and 
two asci protruding from the ruptured 
wall and containing ascospores. S. 
M. COULTER. 
