418 BOTANICAL GAZETTE [DECEMBER 
mitosis.. At anaphase there is present a rather conspicuous centra 
spindle between the two sets of daughter chromosomes (jig. 124a). 
The migration of sporophytic nuclei into the pericentral cell—There 
is only one mitosis within the fertilized carpogonium. The carpo- 
gonium now fuses with the auxiliary cell, which lies between it and 
the pericentral cell (diagram 3, a3). The wall between these cells 
dissolves and a broad communication is formed connecting them. 
A fusion between this auxiliary cell and the pericentral cell follows 
at once, so that the carpogonium is then in free communication with 
the pericentral cell by means of the auxiliary cell. Sometimes this 
communication becomes established as early as the metaphase of the 
mitosis of the fusion nucleus. By means of the passage which is 
established by these cell unions, the two sporophytic daughter nuclei, 
resulting from the division of the fusion nucleus, move down into the 
pericentral cell (figs. 125, 126). 
During the formation of the auxiliary cells from the pericentral 
cell each nucleus in the first three cells of the carpogonial branch 
divides (figs. rrg-122). The daughter nuclei then lie side by side 
in pairs within the cells of the carpogonial branch. While the sporo- 
phytic fusion nucleus is undergoing mitosis, the protoplasmic connec- 
tions between the cells of the carpogonial branch widen, and there is: 
a movement of the cytoplasm along the branch into the carpogonium, 
possibly to furnish nourishment to this cell. 
The communication between the carpogonium and the adjacent 
auxiliary cell is transient,. simply furnishing a passage for the sporo-- 
phytic nuclei into the pericentral cell. After their migration, the 
carpogonium becomes detached from the auxiliary cell and remains 
isolated for a while, without a nucleus, but finally breaks down with 
its three sister cells of the carpogonial branch. 
The formation oj the central cell and the development oj the car po- 
spores.—When the carpogonium becomes separated after its union 
with the auxiliary cell and the passage of its two sporophytic nuclei 
into the pericentral cell, all of the auxiliary cells become more closely 
united with one another. This condition takes. place by the broad- 
ening of the protoplasmic communications that already exist between 
them. New communications are also established between neighbor- 
ing auxiliary cells, so that the entire system becomes closely bound 
