412 BOTANICAL GAZETTE [DECEMBER 
cellular antheridium, in which mitosis, if ever present, has been sup- 
pressed, and the cell as a unit has become the male sexual element. 
FORMATION OF THE PROCARP. 
Development of the carpogonial branch.—The female organ or 
procarp consists in the beginning of a short branch of three or four 
cells. The most important of these is a cell of the axial siphon which 
lies next to the apical cell (diagram 2, A). This cell increases in size 
more rapidly than do the adjacent cells of the filament, so that it is 
very easy to recognize the primordium of the female organ, and 
divides successively to form five peripheral cells, which finally com- 
B E 
DIAGRAM 2.—Development of the carpogonial branch: A, young procarp with 
pericentral cell (pc); B, cross section of A; C, formation of first cell of carpogonial 
branch; D, the four cells of carpogonial branch; E, development of trichogyne (tr) 
from fourth cell or carpogonium (carp) of the carpogonial branch. 
pletely surround it (diagram 2, B). The first stage is illustrated in 
figs. 82-84 and the second in figs. 85-87. The third and fourth 
divisions of the siphon cell have not been figured, but they occur in 
such a manner that the third and fourth peripheral cells are formed 
opposite each other and between the first and second (diagram 2, B). 
The fifth division gives rise to a peripheral cell between the first and 
the fourth, which later develops the carpogonial branch and has been 
called the pericentral cell. 
During every nuclear division concerned with the formation of 
the peripheral cells, 20 chromosomes constantly appear, as shown in 
polar views (jigs. 83, 86), and this number is passed over to the peri- 
central cell. The nucleus in the pericentral cell divides in a direction 
nearly parallel to the axis of the procarp (figs. 89-93), cutting off a 
cell which develops the carpogonial branch (diagram 2, C). ene 
