CHAPTER XXVII 



AGARICALES 



The Agaricales include the gymnocarpous and hemiangiocarpous 

 stage of the chiastobasidial Autobasidiomycetes. They are directly 

 connected to the Polyporales especially to the Dictyolaceae (Cantharella- 

 ceae of most authors) and develop gradually in an angiocarpous direction 

 where the hymenophore and hymenium develop successively in 

 schizogenetically formed cavities within the fructification. The 

 fructification is finally surrounded by a layer of tissue. 



.■/.ii 





^: t v. 



few z ;: -' : *- : - ■•■■■;-': j 



>-.'■ vyi, :::■■■ .*■;.* w.;\~ >.^'- 



,">;■>«: 



wf;-"'v 



5 





Fig. 292. — Hygrophorous miniatus. Diagrammatic sections of developing fructifica- 

 tions. 1. Young undifferentiated fructification. 2. Beginning differentiation into 

 pileus and stipe. 3. Beginning formation of hymenium. 4, 5. Formation of lamellae. 

 (X 20; after Douglas, 1918.) 



The fructifications usually develop as centrally stipitate pilei. In 

 contrast to those of the Polyporales, they are mostly transitory, peren- 

 nation with annual addition of growth zones is unknown in them. They 

 rise on mycelium or mycelial threads as knobs the size of a pin head, 

 elongate subsequently in the direction of the main axis and differentiate 

 into pileus and stipe. 



In the lowest stage, the hymenophore, as in the Cantharellales and 

 Polyporales, develops on the surface gymnocarpously (Fig. 292); the 

 edge of the pileus, however, because of strongly epinastic growth, gradu- 

 ally arches toward the stipe so that its hyphae occasionally intertwine 



451 



