Fertilization of the Floridee. 25 
dary lateral branchlets, formed upon certain cells of the vege- 
tative cell-filament, and these curve in a characteristic manner 
so that their terminal cell approaches very closely with one of 
its corners to the supporting-cell, which at the same time also 
greatly increases. This terminal cell becomes the carpogo- 
nium, the trichogyne of which is much enlarged, but in a 
variable manner, at its base *, before it extends itself exte- 
riorly as a thin capillary process through the small-celled 
cortical tissue; but the supporting-cell of the whole carpo- 
gonial branch becomes the auxiliary cell. 
Different as the arrangement of the carpogonia and auxiliary 
cells may be in all these individual cases, the forms in question 
nevertheless agree in the mode of further development of these 
organs after the fertilization of the carpogonium has taken 
lace. 
First of all the ventral part of the carpogonium becomes 
segmented off as the ovicell. In the next stage of develop- 
ment this ovicell appears emptied of protoplasm, except a 
very small residue (it was but seldom that I found more 
abundant plasma-masses retained in the ovicell, e.g. in Calli- 
thamnion plumula, Nig.), but the closely approximated 
auxiliary cell appears very full of contents and at once com- 
mences a new and rapid growth. 
That in this case the protoplasm (with the cell-nucleus) of 
the fertilized ovicell (or at least a part of this protoplasm with 
the cell-nucleus) migrates into the auxiliary cell can hardly 
be doubted, as the ovicell empties itself to a greater or less 
extent; but the mode of this transference I have hitherto 
been unable to ascertain with certainty in its details. 
In Gleosiphonia open conjugation takes place between the 
ooblastema-cell and the auxiliary cell; but after the migration 
of the protoplasm of the former cell, the latter cell completely 
closes the aperture of conjugation by the new formation of a 
portion of membrane, so that after the conjugation has been 
effected scarcely any trace of it is to be detected (fig. 12). If 
in this case the protoplasm of the ooblastema-cell passed very 
rapidly over into the auxiliary cell, it would depend entirely 
upon chance whether one could succeed in fixing the two cells 
during the conjugation, and so bring the latter to demonstra- 
tion; but with the slower course that the process really follows 
it is not very difficult to find such stages of conjugation in 
fixed material. 
In the forms now under consideration I believe we must 
* Such enlargements of the base above the neck of the trichogyne 
also occur among many other Floridee with densely packed cellular 
tissue (see figs. 33 and 38). 
