MUSHROOM (AGARICUS) 



249 



at their ends to form the superficial palisade-like hymenium (h.) 

 and a round-celled subhymenium (s.). The former comprises 

 two kinds of club-shaped hyphal terminations : some, the 

 basidia (ba.), bear at their apex two, or four, short processes, 

 from the end of each of which a basidiospore is formed, whilst 

 the others are purely sterile, and probably play a part in the 



FIG. 132. The common Mushroom (Agaricus campestris). b*c, and a, 

 successive stages in the development of the fructification (in a the 

 annulus is distinct, but yet unruptured) ; e, transverse section through 

 small part of cap, showing gills ; d, one of the latter enlarged ; /, sur- 

 face of a gill, in section, highly magnified, ba., basidium ; h., hyme- 

 nium ; s., subhymenium ; t., large cells of middle of gill. (After Sachs.) 



detachment of the spores. This method of spore-formation is 

 that characteristic of Basidiomycetes generally, four being the 

 usual number produced. The colour of the spores varies con- 

 siderably in different forms. 



The enormous production of spores in this and other similar 

 Fungi can be gauged by placing the mature caps, with the gills 

 downwards, on a sheet of white paper, when, after a short time, 

 the outline of each gill will be marked by the spores which have 



