152 LEVINE: CYTOLOGY OF HYMENOMYCETES 
the presence of such divisions. The cytoplasm in the cells of the 
stipe contains very large vacuoles. The nuclei are comparatively 
(PL. 4, FIG. 9) large and have typically red-stained nucleoles and 
blue chromatin. In very old stipes the comet-shaped nuclei 
figured by Ruhland also appear. The cell walls of the cells in the 
ring are mucilaginous and these cells may branch. They are 
regularly binucleated (PL. 4, FIG. I0). 
The upper surface of the semiglobular pileus of B. commie 
is covered by a viscid layer of slime. The flesh is thick; the pores 
are relatively short. Small cushion-like glandular bodies are 
conspicuous about their mouths. 
The flesh of the pileus is made up of a meshwork of inter- 
twining hyphae with numerous air spaces. The cortical cells of 
the cap are similar to those in the interior, but their walls are 
gelatinous. In very old material the mucilaginous layer is very 
thick and surrounds almost all of the cells down to the pores. 
The cells of the flesh are short and are almost invariably binu- 
cleated (PL. 5, FIG. 11). I have found however a few cases of cells 
with from three to four nuclei. 
In old material of B. granulatus the trama, the subhymenium, 
and the hymenium are very distinctly differentiated. The trama 
is composed of bundles of long parallel hyphae. The straightest 
filaments are found in the center, while toward the periphery they 
become more interwoven. The terminal branches of the hyphae 
of the trama may be traced directly into the subhymenium as is 
well shown in B. vermiculosus, B. glabellus, and B. pallidus. The 
cell walls are thick and gelatinous, and take a blue color with the 
triple stain. Gelatinous material may also fill the intercellular 
spaces. Two nuclei are found in every cell. Frequently in the 
nuclei of the ring (PL. 4, FIG. 10), flesh, and trama a darkly staining 
granule is found on the nuclear membrane, to which the chromatin 
of the nuclei seems to be attached. The position of this body 
varies; it is sometimes found lying opposite the nucleole but 
frequently it is near it. This body resembles the central body 
described by Harper (1905), for the mycelial nuclei of the mildews- 
The subhymenial cells are short and are binucleated. Their cell a 
walls do not become gelatinous, and their cross walls as also those — 
of the trama and flesh show the characteristic hemispherical pads a 
oy 
