392 



FUNGI 



certain instances of more compact character. Such are the sderotes which 

 are resting states of Coprinus stercorarius (Fr.) (fig. 318), and the rhizo- 

 morphs of Agaricus melleus (L.) (fig. 319), composed of root-Hke 

 branched strands of rnyceHal hyphae, parasitic on the pine. The rhizo- 

 morphs are simply sclerotes with growing-points. From the mycele, of 

 whatever character it be, there arises the compound sporophore by the 

 continued apical or marginal growth of a bundle of hyphge. It is not 

 certain, but it may very well be, that intercalary growth also, in some 



Fig. 320. — Agaricus cavipestris'L.. The common mushroom (natural size). Stages of development 



from a \o e \ b and c in section. (After Luerssen.) 



cases at least, assists in the development. The hymenial surface, which 

 is commonly situated on the under surface of the cap or pileus, is 

 characterised in different genera by being spread over teeth-like projec- 

 tions (Hydnum, L.), radial plates in the numerous species of Agaricus 

 (L.), concentric plates in the small genus Cyclomyces (Kze.), reticulated 

 folds or pores (Polyporus, ]Mich. Boletus, L.) ; such typical characters 

 being united by a wealth of intermediate forms. As a rule these pro- 

 jections are very symmetrical and of regular occurrence, and on them the 

 chief generic characters are based in the classification of the group ; 



