BASIDIOMYCETES 



163 



species, and 'often forms " fairy rings " in woods. H. auriscalpium (Fig. 166) 

 is dark-brown, with stalk placed at the edge of the pileus. It grows on old Fir- 

 cones. H. erinaceus grows on old tree-trunks. The fruit-body is yellow and 

 very large as big as a human head with emergences as much as an inch in 

 length. Irpex has a leathery fruit-body, partly resupinate, partly with free, 

 projecting edge ; the under side bears tooth-like emergences which are arranged 

 in rows, and Irpex thus forms a transition to the Agaricacese. Phlebia is entirely 

 resupiuate, with radially-arranged folds on the free side, and pectinate border. 



FIG. 106. Hydnum auriscalpium, upon a Fir-cone, in different stages of development. 



Order 5. Polyporaceae (Pore-Fungi). An order very rich 

 in species (about 2000 species are described). The fruit-body is 

 of very different forms resupinate, projecting like a bracket, 

 hoof-like, or umbrella-shaped. In some it is fleshy and edible, 

 in others leathery or corky, persisting for several years. The 

 hymenophore is situated on the under side of the fruit-body, and 

 consists of wide or narrow tubes or pores, whose inner surface is 

 clothed with the hymenium (Fig. 167). In some fruit-bodies large 

 cavities are to be found, which have arisen as interstices between 

 the labyrinthine curved and reticulate folds. Chlamydospores are 

 known in some species. Conidia occur very rarely. Many species 

 work considerable damage : some as parasites on trees, others by 

 destroying timber. 



GENERA. Poly poms (Pore-Fungus). The tubes are narrow, accurately fitted 

 together, and forming a thick layer on the under side of the fruit-body, appearing 



