THALLOGENS. 249 
this at length separates, having a double membrane, the cell of the 
spore itself, and the covering or sporangium arising from the 
parent cell in Penicillium and Botrytis. In others, the thread- 
like cells form a spherical swelling at the extremity, from which 
project a number of such prolongations, each of which contains 
a spore, which forms a divided sporangium, as in Mucor and 
Penicillium. 
“In others, as in Gasteromycetes, the ventricular Fungi, the 
thread-like cells, combine into pointed and non-pointed, variously- 
shaped sporocarps, in or upon which are spores of the development 
of which we know nothing. After the scattering of the spores the 
thread-like cells often remain as tender wool, as in the Trichiacea, 
or as delicate net-work (capillitum), as in Stemonitis Cribrarea, and 
the external capsule, generally composed of fine filamentous cells, 
18 then dissolved or ruptured in a regular manner, as in Arcyria 
and Geastrum. 
“In the most highly developed species, the Hymenomycetes, or 
membraneous fungi, elongated pouch-like cells combine so closely 
side by side as to form a membrane or hymenium. Some of these 
enlarge and become sporangia, sending out from one to six points 
at their free extremity, on each of which a spore is developed. 
Thus the filiform cells either form round masses closed in all round, 
called Sporocarps, with cavities in their interior, or they form 
definitely arranged columns in Merisma tubes in Polyporns, or 
lamellee in Dedalea and Agaricus, or clothed on the hymenium, as 
= the Hymeniumeetes. In A garicus the law of their development 
‘8 pretty well understood. At definite points of the flocculent 
mycelium, small hollow heads (volve) are formed, at the bottom of 
the cavity of which there grows a corpuscle, pedunculated below, 
and enlarged into a sperical form at the top. In the lower part of 
this protuberance a circular horizontal cavity is formed, to the 
upper surface of which are attached the tubes, lamella, &c., which 
bear the hymenium. The bottom of the cavity is only formed by 
oe (indusium), separated from the pedicel on its further 
Ce ammepde or loosening itself at once from it and the upper part 
The *same time, it remains as a membraneous ring upon the stalk. 
aila upper part, which supports the hymenium on its lower surface, 
tes subsequently, and appears as an umbrella-like expansion, 
