LEVINE: CYTOLOGY OF HYMENOMYCETES 153 
described above. The basidium mother cells in B. granulatus are 
formed as in all other cases by the division of the subhymenial 
cells. I have not been able to find nuclear or cell division figures 
at this stage. The mother cell divides and the outer cell of the 
two may become either a cystidium or a basidium. Occasionally 
the last nuclear division is not followed by a cell division in the 
basidium mother cell of B. granulatus. A four-nucleated cell results 
(PL. 6, FIG. 45), which elongates and resembles a basidium. It is 
however decidedly different in appearance from the four nucleated 
basidium found in later stages. It is slender, more deeply seated 
in the hymenium and the nuclei are arranged serially. The sub- 
sequent behavior of such cells was not determined. 
Paraphyses have been described as elements of the hymenium 
since the latter part of the 18th century. According to Léveillé 
(1837) the term was first used by Montagne to signify a sterile 
basidium, but in more recent years the function of ‘‘space maker”’ 
has been attributed to them by de Bary (1887), Brefeld (1877), 
Fayod (1889) and Buller (1910). It seems to me that in all cases 
the paraphyses are really immature basidia; as is held also by 
Miss Demelius, who believes that some of them, at least, are, 
as she describes them, ‘‘derzeit nicht fertile Basidien.’”’ In the 
Boleti a number of basidia in similarly advanced stages are fre- 
quently found developing in close contact with each other. 
The cystidia of the Boleti appear either singly or in clusters. 
Such clustered cystidia are not uncommon, for Patouillard (1887), 
Demelius (1912), and Knoll (1912) have also found them. In 
B. granulatus such clusters are covered by a gelatinous excretion 
and are visible, as noted above, as minute dark specks about the 
mouths of the pores and over the surface of the hymenium. The 
individual cystidium is club-shaped; the entire cluster (PL. 7, FIG. 
12) forms a cushion-shaped mass. Cystidia in all stages of de- 
velopment may be found in a single cluster. Fic. 12 “a,” PL. 7, 
shows very young cystidia which are approximately the size of the 
mature basidia. Fic. 12 “‘b,” 12 ‘‘c,” PL. 7, represent later stages 
of their development. The young cystidium (PL. 5, FIG. 13) shows 
a dense granular cytoplasm, which is somewhat fibrillar in the 
upper part of the cell; vacuoles are also present. The young 
cystidium is regularly binucleated; the nuclei are in all essentials 
similar to those found in the basidium. : 
