Nuclear Phenomena in the Smuts. 
493 
All the cases of union so far discussed are between cells which 
are either themselves coenocytic or belong to organisms which 
in some stages of their development form coenocytic cells. The 
fusing conidia of the smuts are uninucleate. The fusing spores 
o Protomyces contain each several nuclei. The tendency among 
the fungi to form multinucleated cells may be another expres¬ 
sion of some fundamental quality of their protoplasm which also 
leads to the cell fusions which have been described. How a 
binucleated or several nucleated cell arising by fusion would 
differ from a binucleated or several nucleated cell which became 
so by internal nuclear divisions, is not certain, especially when 
the fusing cells are separated in descent by only one or a few 
cell divisions. 
Oltmanns’ recent researches on the nuclear phenomena in the 
sexual reproduction of the red algae, have furnished a very in¬ 
teresting case of cell fusions without nuclear fusions. They are 
the cell fusions which Schmitz regarded as secondary fertiliza¬ 
tions. According to Oltmanns, in the forms where these sec¬ 
ondary fusions occur, Dudresnaya purpurifera for example, the 
sexual fusion of energides — spermatium and egg with their 
nuclei — takes place in the carpogon. From the carpogon grow 
out typically three branches (“ooblastema threads” of Schmitz, 
“carpogenous filaments” of Oltmanns). The fertilized egg nu¬ 
cleus divides, and daughter nuclei are carried along in the car¬ 
pogenous filaments. The carpogenous filaments fuse with ordi¬ 
nary vegetative auxiliary cells of the branch which bears the 
carpogon, but no nuclear fusions occur. The sporogenous ener- 
gide simply uses the material of the cells with which it fuses for 
its own further vegetative development. After these fusions 
the carpogenous filament proceeds still further to fuse with spe¬ 
cial auxiliary cells on the ends of branches in the various parts 
of the plant. Here again no nuclear fusions occur. The nuclei 
of the carpogenous and auxiliary cells repel rather than attract 
each other. In the fusion cell thus formed the sporogenous nu¬ 
cleus divides; one daughter nucleus passes on with the further 
growth of the sporogenous filament, and the other remains in 
the fusion cell, appropriates its protoplasm, and by subsequent 
1 “Zur Entwicklungsgeschichte der Florideen,’ , Flora , 1898. 
