Nichols—Binuclealcd Cells in Some Basidiomycetes. 51 
material, a means of spreading the species in the substratum and 
are capable of retaining their vitality during a long dormant 
period. 
Poria. (Fig. 19.) 
The rhizomorphs of a species of Poria were collected in April 
from the underside of a board sidewalk where they had hiber¬ 
nated. Thus they were in a resting rather than the active 
growing condition of the other species described later. The 
main strands were about an eighth of an inch in diameter. 
These branch dichotomously a few times and from them a num¬ 
ber of very slender branches are formed. These branches ex¬ 
tend in every direction over the substratum; they subdivide 
freely, the branches frequently anastomosing and flattening out 
to form web-like expansions. The younger portions of the 
strand are a dull yellow while the older portions are coated with 
a yellowish brown layer. 
Their structure is very simple. The entire strand is formed 
of slender hyphae which are very straight, only twining about 
each other slightly. At the center a large number of the hyphae 
have lost their contents and the walls are very thick. But 
among them are other hyphae with thin walls and rich proto¬ 
plasmic contents. The cytoplasm is filled with small deeply 
staining bodies but there are no crystals. Towards the surface 
these thin walled hyphae become fewer and finally disappear 
leaving the outer layer formed wholly of thick walled hyphae 
(Fig. 19a). In a number of the thin walled cells two nuclei 
were found. They were very small and dense lying near to¬ 
gether at the center of the cell. In some cases the deeply stain¬ 
ing granules were so abundant and so closely packed that it was 
impossible to distinguish the nuclei. Among the hyphae there 
were numerous openings or pockets filled with octahedral crys¬ 
tals which dissolve slowly in hydrochloric acid indicating that 
they are calcium oxalate (Fig. 19c). Just beneath the surface 
layer of thick walled hyphae there is a layer of similar crystals 
very closely packed together (Fig. 19b). 
