Nichols—Binucleated Cells in Some Basidiomycetes. 
57 
CONCLUSIONS. 
The results obtained from the above studies show that the bi- 
nueleated cells do not originate through the formation of any 
special reproductive apparatus. Neither is there any structure 
in the formation of the hyphae or in the cells of the hyphae that 
indicates in any way where the binucleated cells will first ap¬ 
pear. That they arise previous to the formation of a carpophore 
in a large number of forms is very evident. The long series of 
binucleated cells found in the mycelial strands or rhizomorphs of 
Poria, Pholiota, Lepiota, Dictyopliora and Lycoperdon show that 
in these forms the origin of the binucleated cells is only distantly 
associated with the formation of a carpophore and it is probable 
that many strands never develop carpophores. In Hypholoma 
verplexum there is an expanded mass of mycelium with binu¬ 
cleated cells formed previous to the appearance of a carpophore. 
In many forms in which there is not any specialized structure 
between the filamentous mycelium and the carpophore, as in 
Crepidotus, Corticium, and in Coprinus ephemerus it was found 
that the cells of the mycelium in the substratum in the region of 
the carpophore were regularly binucleated. Binucleated cells 
were also observed in the cells of the mycelium of Ilypochnus by 
Harper. As was mentioned previously, he w'as able to trace the 
series of binucleated cells from the hymenium into the mycelium 
in the substratum. The above cases show' that the formation of 
binucleated cells is not necessarily followed immediately by the 
formation of a carpophore. 
Further in the fairly complete series of stages from the germi¬ 
nation of the spore to the mature carpophore vdiich w r ere ob¬ 
tained for Hypholoma perplexum and Coprinus ephemerus the 
same fact appears. A summary of the development of these 
species is as follows: 
The spores of both species contain two sister nuclei which at 
germination pass from the spore into the germ tube. In Coprinus 
the nuclei divide very rapidly, forming a multinucleated germ 
tube which may contain twenty or thirty' nuclei before the first 
wall is formed. The nuclei do not divide as rapidly' in the germ 
tube of Hypholoma so that it seldom contains more than six or 
