in the northern states. The species of Polyporus with small 

 round pores are more numerous ; some are confined to special 

 kinds of wood while others do not seem to show any preference 

 for the substratum on which they grow. Thus a species which 

 has passed as Polyporus lucidus, but which is a wholly different 

 species, grows only on the hemlock, and its polished surface 

 looking as though smeared with shellac renders it very easy to 

 distinguish. P. bctulinus, with shapely form and pure white con- 

 text, is confined to the white birch and is very abundant wherever 

 its host is found. P. rimosus, with a cracked and fissured pileus, 

 is common on the black locust (Robinid) from New York City to 

 central Indiana and southward. In the fall the common willow 

 {Salix alba) bears a rather fragrant species of a genus too closely 

 allied to Polyporus, Trametes snaveolens. All these species and 

 many others are confined to single kinds of trees and can readily 

 be known by their peculiar habitat. Other genera of the pore- 

 bearing fungi are also confined to single species of trees. Al- 

 most every old chestnut stump in the vicinity of New York City 

 is more or less covered with the pilei of Daedalca quercina, with 

 its thick corky texture and its coarse labyrinthine pores which 

 almost form a link to lamellae. True lamellae are found in Leu- 

 sites, of which the common species with a brown context ^Leu- 

 sites sepiarid) is confined to the wood of coniferous trees, while 

 the common species with a white context (Lensites behdiud) is 

 more widely distributed on the wood of deciduous trees and is 

 everywhere common, its velvety pileus often covered with a 

 growth of green algae. 



Certain of the species of Polyporus are annual, forming a single 

 layer of pores, though some of these occasionally build out a new 

 mycelial surface beyond the borders of the old growth. Among 

 these, three species are everywhere common, and all of them 

 present themselves under a variety of forms. Polyporus per- 

 gamenus, with lacerate pores and thin pilei often tinted beauti- 

 fully with purple when young, is the most widespread species, 

 often covering the whole surface of a standing tree trunk or a 

 recently fallen dead log. P. versicolor, still more protean in char- 

 acter, may be recognized by its thin context, white pores and 



