Nichols - Binucleated Cells in Some Basidiomycetes. 61 
dence Maire has formulated a theory of the alternation of gener¬ 
ation in the Basidiomycetes. He believes that the origin of 
the binucleated cell is comparable to the fertilization of the 
higher plants. The carpophore having cells with paired nuclei 
corresponds to the .sporophyte. The fusion of nuclei in the basid- 
ium is then not a fertilization but a reduction-process. Black¬ 
man’s discovery that in the rusts the binucleated cells arise by 
an actual cell fusion is strong evidence in favor of this view 
and Blackman develops the conception into very satisfactory 
form so far as the rusts are concerned. It is possible that the 
origin of binucleated cells in the ordinary course of mycelial 
growth as described above may have come to serve as a sub¬ 
stitute for cell fusions and that thus the stages of development 
with binucleated cells in the Basidiomycetes may be considered 
the equivalent of a sporophyte. Since, however, the point or 
points at which binucleated cells arise is very variable such a 
sporophyte can by no means be considered as representing a so 
definitely differentiated stage of development as does the sporo¬ 
phyte of the moss or fern. 
