246 



FORMS OF THE AGARICALES 



of this family form shelf-like outgrowths on trees and are there- 

 fore known as bracket fungi (Fig. 170, B-D). Professor Duller 

 estimated that a single pore in one species of this group which he 

 found growing upon a decaying elm, produced no less than 1,700,- 

 000 spores and that the entire bracket, about 250 sq. cm. in area, 

 formed over eleven billion spores. The combined annual output 

 of the ten brackets growing upon this tree exceeded by fifty times 

 the population of the globe. This enormous spore production 



Fig. 170. Pore forms of the Agaricales: A, Boletus, showing fleshy pore- 

 bearing layer, p. B, top view of a woody, bracket form, Elfvingia. The 

 concentric Hnes represent the annual growth. C, section of a similar form, 

 showing three layers of pores that represent three years' growth. D, en- 

 larged view of under surface, showing one of the pores with hymenial layer. 



is characteristic of nearly all of the Agaricales and it is not sur- 

 prising that a bit of dead wood or piece of lumber can not be 

 exposed without being infested with the spores. 



E. Boletaceae or Fleshy Pore Fungi. — The members of this 

 family are generally characterized by a stalk and a pileus which 

 bears pores, the latter being easily separable as a layer from the 

 pileus (Fig. 170, A). 



F. Agaricaceae or Gill Fungi. — These fungi more commonly 

 assume an umbrella form, although some of them are of the 

 shelving bracket type (Fig. 167). The hymenium is arranged 

 on the surface of gills or plates. Many of them are highly 

 prized for the table, though they contain comparatively little 

 nourishment, and must be regarded as relishes rather than foods. 



