406 BOTANICAL GAZETTE [DECEMBER 
it seems possible that the nuclear membrane may be formed as the 
result of the contact of the caryolymph with the surrounding cyto- 
plasm (fig. rz). Such conclusions were drawn by Lawson (44) and 
‘GrécorrE and WycGaeErts (36) in their studies of the telophase of 
mitosis. The chromosomes later lose their individual outlines and 
the mass becomes transformed into a chromatin network (fig. 12). 
A new nucleolus is then formed in the daughter nucleus. 
No mention has yet been made of the manner of cell division. The 
coarse alveolar structure of the cytoplasm taken as a whole persists 
during mitosis, the kinoplasm associated with the division of the 
nucleus remaining distinct from the alveolar cytoplasm and reacting 
more deeply to the plasma stains. The daughter nuclei when formed 
lie above one another in the germinating tetraspore. Before they 
have attained their full size a cleavage furrow appears at the middle 
region of the cell which is at first very shallow. The central spindle 
that lay between the two groups of daughter chromosomes has entirely 
disappeared before the cleavage furrow is formed, so that the center 
of the cell is filled by cytoplasm which presents a very coarse alveolar 
structure, especially in the middle region, where the cleavage furrow 
begins (fig. 13). This furrow proceeds inward, the only visible assis- 
tance in its development being the extensive fusion of vacuoles by 
the breaking of their limiting membranes so that less resistance is 
presented to its progress. Finally, the furrow reaches nearly to the 
center of the cell (fig. 14), so that the tetraspore becomes divided 
into daughter cells, which are in communication by a strand of 
protoplasm, as is so generally characteristic of the red algae. 
THE FIRST MITOSIS IN THE GERMINATING CARPOSPORE. 
The carpospore on its escape from the cystocarp is somewhat 
pear-shaped, but it gradually assumes an oblong or spherical form 
while floating in the water. The coarse alveolar structure of the 
cytoplasm, the arrangement of the plastids, and the fine linin net- 
work within the nucleus (fig. 15) are similar to those of the tetraspore- 
Moreover, the first mitosis takes place at about the same period after 
their escape from parent plants, namely after about fifteen hours. 
The history of the mitosis in the germinating carpospore is S0 
