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Saprolegnia shows a 
striking case of the loss 
of sexuality. In this 
genus we may find fune- 
tional antheridia, an- 
theridia which do not 
function, or the entire 
absence of antheridia. 
SUBCLASS ASCOMYCETES 
The Ascomycetes con- 
sist of fungi of various 
forms but characterized 
by having 
borne in asci. The asecus 
is a saclike, commonly 
ascospores 
cylindrical structure usually containing eight ascospores (Hig. 
362), but the number of spores may vary from two to many. 
In a few cases the 
asci are borne sin- 
gly, but in the vast 
majority of species 
they are produced 
in a layer, called 
the hymenium, which 
contains many asci, 
among which are 
the numerous sterile 
filaments, the para- 
physes (Figs. 3862, 
363). In some cases 
the hymenium oc- 
curs as an outer COV- 
ering of. the fruit 
body, while in others 
Fia. 
Right, morel (Morchella), in which the hymenium 
covers the upper portion ; left, truffle (Tuber brumale), 
in which the asci are inclosed within a sterile cover- 
ing. (X 3) 
565. 

Edible ascomycetes 
