335 
Nemalion multifidum , Ag. 
others may get part way down the trichogyne (Fig. 22). At the time of 
passage through the trichogyne the male nucleus contains a large homo- 
geneous nucleole, and is therefore in a resting condition (Figs. 30-23). In 
those forms in which the male nucleus is in prophase at the time of escape 
of the spermatium, and in which no division takes place, the male nucleus 
is reported to pass down the trichogyne in prophase, as a group of small 
bodies, each a chromosome. This is the condition described for Polysiphonia , 
Griffithsia corallina , and Scinaia. 
After the male nucleus has passed into the carpogonium, the trichogyne 
is cut off from the carpogonium by a cleavage plane (Fig. 32), and later by 
a cell-wall (Figs. 21, 22, 24, 31). The supernumerary male nuclei therefore 
are left behind in the trichogyne (Figs. 21, 22), which remains for sometime 
after fertilization, but finally withers and disappears (Text-fig. 3). 
Oogenesis. 
The procarp arises laterally from near the base of a vegetative tuft. 
It is easily recognized even in the one-celled condition by its form, being 
broader and shorter than the vegetative branches. The mature branch 
most frequently consists of four cells, but five and three are not uncommon, 
and two- or six-celled pro carps are occasionally seen. The cells of the 
procarp have nuclei of the usual type. Each cell also possesses a chromato- 
phore. In the basal cell this generally has a form more or less typical 
for any interior vegetative cell. The chromatophore becomes less and less 
well developed, however, in the cells above, until in the carpogonium and 
sub-carpogonial cell all sign of its pyrenoid structure is gone and the 
chromatophore consists merely of a dense mass of material very often 
surrounded by a narrow ring (Fig. 29). The cells before the fertilization of 
the carpogonium are entirely free from the darkly-staining bodies which are 
so characteristic at a later stage; 
After the procarp has attained its full length, the terminal cell or 
carpogonium gives rise at its tip to a swelling which elongates and develops 
into the trichogyne (Figs. 26-29). At the base of the carpogonium is 
found the nucleus, which is quite large and possesses a prominent nucleolus 
and a distinct light-staining reticulum. Above the nucleus lies the chro- 
matophore. Occasionally the position of the nucleus and chromatophore 
is reversed (Figs. 26, 27). 
I have given special attention to the question of the presence of 
a trichogyne nucleus. I have examined many hundreds of unfertilized 
carpogonia with their trichogynes in every stage of development, and in 
only a few instances have I found indications of such a body. In two of 
these cases an extra nucleus was very clearly shown (Figs. 27, 28), which of 
course would constitute the so-called trichogyne nucleus. It should be 
noted, however, that in both of these cases the extra nucleus is not in the 
