TllALLOl'II YTKS : FUNGI 



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a littlo sphere, which suggested the nanio MicfiiKplui'ni 

 (l''ig. 241). The heiivy wall of the ascucarp bears beauti- 

 ful branching hair-lilce appendages (Fig. 342). 



Bursting the wall of tliis 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. 

 24'i). The ascocarp, there- 

 fore, is a spore case, just as 

 is the cystocarp of the Ked 

 Alga3 (S 174). The delicate 

 sacs within arc the a.vrt, 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 as.m- 

 xpnrc. 



it is these peculiar moth- 

 er cells, or asci, which give 



name to the group, and an Ascomycete, Ascus-fuugus, 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 ) coiiUHh, formed from a hyphal branch by aljstric- 

 tiou, by which the mycelium may spread rapidly ; and (2) 

 asmspores^ formed in a mother cell aiul protected liy 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 

 Algie and Phycomycetes, no sexual spore probably being 

 formed, but a heavy-wallcd ascocarp. 



185. Other forms. — The mildews have been selected as a 

 simple illustration of Ascomycetes, but the group is a very 



Fio. 242. Ascocarp of the lilac mildew, 

 showing brandling appendages and 

 two asci protriulinj^ from the ruptured 

 wall and containing ascospores, — S. 

 M. CoULTEll. 



