THE PHYLOGENY OF THE GENUS BRACHIOMONAS 83 
from the mother cell, and the form then attained persists 
through the life of the individual. In newly formed zoospores, 
usually, but not always, the protoplast and chromatophore ex- 
tend into the posterior horn so as to fill it completely. In 
older individuals the protoplast gradually retracts so that a 
considerable portion of the horn, or finally all of it is empty. 
The pyrenoid and red eye-spot regularly lie on the same side of 
the cell, and the nucleus on the opposite side; as in B. sub- 
marina, this is most clearly shown in cells momentarily resting 
with one of the poles directed upward (Fic. 32). 
As in the other species, asexual reproduction is accomplished 
by division of the protoplast into four or eight daughter cells 
which develop the characteristic form while the mother cell 
still retains its cilia in active movement (FIGs. 35, 36). 
In sexual reproduction, gametes may be formed to the 
number of thirty-two in one mother cell, which retains its 
motile condition until they are completely developed (Fic. 40) 
just as in the case of asexual reproduction.. The gametes are 
similar in form to the asexual cells, but much smaller, lacking 
a cell wall, and furnished with relatively longer cilia: they 
also seemed to be more apt to show angularity in the middle 
region than the asexual cells. Usually there was a slight differ- 
entiation between the pair, a smaller and more fusiform gamete 
conjugating with one slightly larger and more angular (Fics. 
41, 42). Meeting by the ciliated anterior ends, the fusion is 
lateral, resulting in a quadriciliate zygote of ovoid-pyriform 
shape which swims actively, and may for some time show the 
two nuclei, two pyrenoids, and two linear eye-spots (FIG. 43); 
when momentarily at rest the four long cilia trail backwards. 
Finally the nuclei fuse, the cilia disappear (Fic. 44) the form 
becomes spherical, and the thick wall of the resting zygospore 
is developed (Fic. 45). After some days the cell contents 
assume a reddish orange color similar to that of the aplanospore 
of this species and of B. submarina 
Brachiomonas simplex sp. nov. 8B. cellulis a acca 
majoribus, Ree oviformibus quidem sed a 
partem in curvatum productis, brachiis quae c ore 
hujus Ge apetiet habent aut omnino a nae a evolutis 
tantummodo in 2-4 gibbos undatos; 
ad polum autem anteriorem globosis vel saalba cobich  pantals 
exornatis: chromatophoro cellulam prope complente aut non 
