The Biology of Polyporus Pargamenus Fries 39 
thin dentate, but becoming lacerate, more or less concentric 
lamelle; spores smooth, hyaline, cylindric (rod-like in dorsi- 
ventral view but allantoid and obliquely apiculate in lateral 
view), curved, 5-6.5 by 2-2.25 u; cystidia of variable occur- 
rence; when present, conspicuous, hyaline, blunt, and capi- 
tate with an incrustation of mineral matter, 15-25 by 4-5 uy; 
projecting 0-10 u.; hyphae of the context hyaline, 3-4 v in 
diameter. 
Variation BHxhibited by the Sporophores of Polyporus Par- 
gamenus.—In the above technical description an attempt has 
been made to make the descriptive terms somewhat broad 
and far-reaching — an absolute necessity when describing a 
species comprising half a dozen more or less distinct forms. 
The following account of Peck (1880, pp. 36-37) is cited 
here since it accurately portrays the range of variation 
assumed by this plant in the eastern United States. 
“ Polyporus pergamenus, Fr. The typical form of this species, 
according to the description, has the pileus coriaceo-membran- 
aceous, rigid, tomentose, concentrically sulecate, white; the pores 
seriately placed, pallescent and produced into very thin dentate 
plates. Its habitat is said to be pine, and its locality Arctic 
America. The species, as now understood, proves to be a very 
common and very variable one and includes several synonyms. 
In Ravenel’s Fungi Car. Exsice., Fase. 1, No. 13, Polyporus 
laceratus, Berk., is represented to be a synonym of this species. 
Dr. Berkeley himself does not give it as a distinct species in his 
Notices of North America Fungi, though it was founded on 
specimens from New Orleans, from which we infer that he does 
not regard it as a good species. According to the description 
it scarcely differs from Polyporus elongatus, Berk., except in its 
shape and its larger pores. The former difference is of little 
value for P. elongatus is known to vary very much in shape and 
size. But P. elongatus, according to authentic specimens received 
from Dr. Michener, can scarcely be regarded as anything more 
than a mere form, or perhaps variety, of P. pergamenus. For 
of this species we have in this State (New York) two prevailing 
forms. One form has the pileus tomentose, concentrically sulcate 
and white, and its pores become paler with age and are at length 
produced or lacerated into thin dentate plates precisely as 
required by the description. But it differs from the type in gen- 
eral, though not always, having the pileus too thick to be called 
membranaceous, and in the pores not being seriately placed. 
These slight differences, however, are of but little account in 
_ such a variable plant as ours is known to be, and there can be no 
doubt that it should be referred to P. pergamenus, The other 
