174 LEVINE: CyTOLOGY oF HYMENOMYCETES 
2. The mycelia of Collybia velutipes, Polyporus adustus, 
P. betulinus, P. destructor, P. versicolor, and Coniophora cerebella 
propagated from old cultures are made up of long series of binu- 
cleated cells. Clamp connections, hyphal anastomoses, and the 
so-called protoplasmic connections are numerous in all the mycelia. 
3. The cells of the mature stipe of Boletus granulatus are all 
multinucleated, while the cells of the ring are binucleated. The 
cells of the flesh and trama of B. granulatus are binucleated. The. 
cells of the subhymenium are binucleated in all the species of 
Boletus studied. 
4. The cystidia of the Boleti occur either singly or in small 
clusters forming gelatinous granules. In B. granulatus these 
cushion-shaped ‘‘granules’”’ are abundant at the mouths of the 
pores and scattered over the hymenium. The individual cysti- 
dium is binucleated. It is club-shaped and is deeply seated in 
the hymenium. The cystidia of the Boleti appear to be in some 
sense glandular in their functions. 
5. The nuclear phenomena in the basidium are eieal in » all 
the species of Boletus examined. Fusion of the two primary — | 
nuclei of the basidium was observed in Boletus granulatus»B. ver- 
sipellis, B. glabellus, B. vermiculosus, B. castaneus, B. albellus, and 
B. chrysenteron. 
6. The long axes of the spindles in both divisions are commonly _ 
transverse to the long axis of the basidium. Variations, however; 
appear in which the spindles are almost perpendicular to the 
transverse axis of the basidium. Centrosomes and well-developed 
astral rays are regularly present. 
7. The chromosome number in the first division is from six 
to eight in Boletus granulatus, B. castaneus, B. albellus, B. vermicu- — 
losus, B. versipellis, and B. chrysenteron. In the second division 
the exact number cannot be determined. It is, however, always 
more than two. 
8. At the end of the second division the centrosomes become 
attached to the walls of the basidium and the four daughter E 
nuclei are reconstructed in close connection with them. As the : 
nuclei move downward in the basidium they maintain their — 
connection with the centrosomes by means of fibrillar strands 
which are, perhaps, analogous to astral rays. The fibril 
strands apparently pull the nuclei into the spores. 
