DEVELOPMENT 
H 
The basidia are the spore-producing cells. The spores are 
borne on stalks ( sterigmata ) at the apex, usually four to each 
basidium, as in the common mushroom, though this 
species is frequently incorrectly represented as bearing 
only two. 
The paraphyses are smaller than the basidia, and are 
always barren. They are probably atrophied basidia, and 
proceed from the same hyphse. Their functions are un¬ 
known. 
The cystidia are large barren cells which project beyond 
the others. They originate from the hyphae of the trama, 
not from the sub-hymenial layer. They are supposed to 
be hypertrophied basidia. It has been suggested that they 
serve to keep the gills apart, and to protect the basidia from 
slugs and insects. They do not occur in all agarics, and 
are more frequent amongst species with coloured spores. 
Some agarics spring from sclerotia. 
ASCOMYCETES 
This order includes two sub-orders—Pyrenomycetes and 
Discomycetes.* 
The Pyrenomycetes are characterized by having the 
ascus-bearing surface always enclosed in a flask-shaped 
body, the perithecimn , provided with a very short neck, 
through the mouth of which (the ostiolum) the spores 
escape. 
The pevithecia may be isolated (as in Sphseria) or numerous, 
and imbedded in a fleshy structure, the stroma , their ostiola 
opening on its surface (well seen in Xylavia polymorpha). 
* “As would be expected in such a large assemblage of forms, the 
two groups closely approach each other at certain points. Genera and 
even families have from time to time been removed from one sub-order 
to another, depending on individual opinion ’’ (Massee, “Textbook of 
Fungi,” p. 281). 
