58 College of Forestry 
for Hydnum ochraceum Quél., especially when the walls are 
thus broken up in the young stages of the sporophore, as is 
often the case with Polyporus pargamenus. 
Color.— The color of the pile of Polyporus pargamenus 
varies greatly in different sporophores, the variation appar- 
ently being influenced by the host as well as by other external 
factors. For ex ample, the writer has noticed and is corrobo- 
‘ated in his observation by the experience of Mr. C. G. Lloyd 
who states that he finds that the most intensely colored 
sporophores occur on wild cherry. In color there may be 
all gradations from white, at the beginning of the appear- 
ance of the fruit bodies, or in the case of their growth in the 
absence of light, to gray or brownish-gray with age and 
weathering. "The context of the pilei is imiformly: white 
but usually becomes somewhat discolored with age. In fresh 
growing specimens the hymenial surface is frequently tinted 
violaceous, sometimes very strikingly so. This peculiar col- 
oration, however, usually is a transient one. 
Either coincident with or within the individual zones of 
growth there are a number of variously colored zones of all 
color gradation from buff to brown. While these colored 
bands are prominent they usually are not so striking as 
those exhibited by Polyporus versicolor (.) Fries. This 
color, which to some extent intensifies the zoning, is largely 
dependent upon the light. Bayliss (1908) has shown that 
the coloration in Polyporus (Polystictus) versicolor is due 
to the presence of a diffuse-yellowish pigment, which, on 
exposure to light, gradually changes into sepia brown gran- 
ules. When the sporophore first makes its appearance “it is 
always white as is also any new growth which takes place 
at the margin of the pileus. In P olyporus versicolor Bay- 
liss found that after three or four days a pigment is 
devoloped in the hairs which cover the upper part of the 
sporophore, and also in the surface of strands of hyphee from 
which these hairs arise. According to the same author these 
pigment granules cause the hairs and superficial hyphe to_ 
vary from buff to dark brown, according to the intensity 
