Nichols—Binucleated Cells in Some Basidiomyceles. 31 
the development of the young carpophore. From the older por¬ 
tion of the mycelium a perpendicular hypha very rich in proto¬ 
plasm arises. This hypha branches profusely forming a dense 
snarl from the center of which a bundle of parallel hyphae de¬ 
velop forming the first indication of the stipe. Lateral branches 
are formed increasing the size of the mass and at the same time 
the stipe grows rapidly in length. The pileus and gills are 
differentiated very early in the development of the fruit body. 
Brefeld found no evidence of the existence of sexual organs at 
the formation of the carpophore. 
With the study of the nuclear phenomena new stand-points 
arose. The work of Rosen (21), Rosenvinge (22), Wager (26, 
27, 28), and Dangeard (5) has established the fact that the 
cells of the carpophore are frequently multinucleated while the 
basidia are at first binucleated. In typical basidia the two 
nuclei fuse and the fusion nucleus divides into the four spore 
nuclei. 
Maire (15) found that the cells of the young carpophore are 
binucleated and that the cells of the hymenial layer never have 
more than two nuclei, but that the cells of the stipe and pileus 
may become multinucleated through the amitotic fragmentation 
of the two nuclei originally present. The young basidiimi when 
it is formed from the hymenial ceiis receives two and only two 
nuclei which unite to form the large fusion nucleus of the basid- 
ium. He further states that the nuclei in the series of binue- 
leated cells in the young carpophore divide by conjugate divi¬ 
sions so that the two nuclei which fuse in the basidium are of 
widely different origin. But his evidence is not conclusive on 
this point. 
Maire describes the division of the nucleus in the basidium in 
detail. The nuclear membrane disappears and the spindle ap¬ 
pears at about the same time. The chromatin filaments break 
up into irregular granules or protochromosomes which are placed 
on the spindle without any definite order. At the end of the 
prophase these protochromosomes unite into two definite chro¬ 
mosomes. That the formation of only two chromosomes is not 
universal among the Basidiomycetes as Maire assumes has been 
shown by Wager, Ruhiaud and others. Maire states further 
