494 Harper—Nuclear Phenomena in the Smuts. 
divisions accompanied by cell divisions forms the mass of car- 
pospores. The original nucleus of the auxiliary cell gradually 
becomes disorganized and disappears. The whole process con¬ 
sists in the parasitic development of the nuclei derived from the 
fertilized egg in the auxiliary cells of the mother plant. It is 
analogous to the parasitic development of the sporophyte on 
the gametophyte in the mosses. The fusions of sporogenous 
(ooblastema) filaments with the auxiliary cells is purely a nu¬ 
tritive process, and adds thus a most interesting further type 
of cell fusion to those already enumerated. The whole process 
of the presumably chemotactic attraction of the cells for each 
other, the breaking down of the cell walls, and the union of the 
cytoplasmic masses, is carried out solely for the purpose of 
supplying the sexually produced energide with material for the 
production of a mass of carpospores. It is a case of parasitism 
in a sense; and yet the ceil fusion is in no respect like the pene¬ 
tration of a host plant cell by a haustorium or a swarm spore, 
as it occurs in the case of the parasitic fungi. The hausto¬ 
rium maintains its own bounding membrane and simply devours 
the killed and liquefied substance of the host cell by absorption. 
The unions of the sporogenous and auxiliary cells is a real fusion. 
The fused cells have a common plasma membrane. The cell wall 
also, which encloses the fusion cell, as Oltmanns points out, is 
in part the wall of the auxiliary cell and in part the wall of the 
sporogenous filament. 
These investigations of Oltmanns must be considered as of 
the greatest importance, not only in bringing clearness out of 
the chaos which has hitherto existed in our notions of sexuality 
in the red algae, but also because they bring into sharp con¬ 
trast the sexual fusion of cells and nuclei and cell fusions 
which have a purely vegetative and still well defined signifi¬ 
cance. The independence of the phenomena of nuclear and cell 
fusions is clearly brought out and the suggestion given, that 
while each may be of great importance to the organism, their 
significance may well be quite distinct. These secondary cell 
fusions have at least a nutritive function and may have others. 
In this connection the view of Iwanzoff 1 that normal conju- 
1 N. Iwanzoff, “Physiologische Bedeutung u. s. w.” Bull. Sog. Imp., 1898. 
