The Biology of Polyporus Pargamenus Fries or 
as a direct outgrowth of the latter; it is composed of hyphee 
of normal size that bear numerous clamp connections. In 
Polyporus pargamenus the clamp connections form as lateral 
outgrowths of one cell fusing with the cell beneath it, the 
separating wall sometimes being formed before the clamp has 
fused with the next cell (Plate XIV, Fig. 1). The secondary 
mycelial system consists of an intricately branched network 
of hyphee comprising both large hyphe with distinct thin 
walls, and hyphee of smaller diameter, formed by the repeated 
branching of the larger ones; these hyphx in turn branch 
and rebranch. At certain points along the larger hyphe 
short branches are given off which divide ver y rapidly into 
the finest threads which penetrate the cells in all directions. 
Connections between adjacent hyphz occur frequently; also 
rhizomorph-like masses where large numbers of hyphze have 
fused together more or less. The latter occur most abun- 
dantly in the vegetative mycelium growing over the surface 
of blocks of Sand 
Polymorphism.— Lyman (1907, p. 127) defines the bas- 
idiospore, borne on the basidium which is the characteristic 
organ of the group, as the primary reproductive body of the 
Basidiomycetes, and denotes all other spore forms, that is, 
those not borne on basidia, as secondary spores. According 
to Lyman (1. ¢.) the secondary spores thus far known to 
belong to species of Basidiomycetes are of four types: (a) 
chlamydospores — encysted vegetative cells; (b) oidia — the 
dissociated cells of vegetative hyphe; (c) budding cells — 
produced by a yeast- like growth; and (d) conidia — éxo- 
genously abjointed cells which show more uniformity of size 
and shape than do the other types of spores mentioned, and 
are produced on more or less specialized structures called 
conidiophores. 
Oidia.— In the cultures of Polyporus pargamenus the 
division of the hyphze into oidia was preceded by a contrac- 
tion of the protoplasm, leaving empty hyphal walls at numer- 
ous points along the filament. Later the hyphze become 
divided into many short cylindrical cells with rounded ends, 
