he young cells, assuming their green
color as the cells approach maturity.

The plant multiplies non-sexually by means of special branches that
may become detached, but there are no non-sexual spores formed.

The sexual organs have already been noticed arising in pairs at the
joints of the leaves. The ooegonium is formed above, the antheridium
below.

The young ooegonium (_F_, _O_) consists of a central cell, below
which is a smaller one surrounded by a circle of five others, which
do not at first project above the central cell, but later completely
envelop it (_G_). Each of these five cells early becomes divided
into an upper and a lower one, the latter becoming twisted as it
elongates, and the central cell later has a small cell cut off from
its base by an oblique wall. The central cell forms the egg cell,
which in the ripe ooegonium (_L_, _O_) is surrounded by five,
spirally twisted cells, and crowned by a circle of five smaller
ones, which become of a yellowish color when full grown. They
separate at the time of fertilization to allow the spermatozoids to
enter the ooegonium.

The antheridium consists at first of a basal cell and a terminal
one. The latter, which is nearly globular, divides into eight nearly
similar cells by walls passing through the centre. In each of these
eight cells two walls are next formed parallel to the outer surface,
so that the antheridium (apart from the basal cell) contains
twenty-four cells arranged in three concentric series (_G_, _an._).
These cells, especially the outer ones, develop a great amount of a
red pigment, giving the antheridium its characteristic color.

The diameter of the antheridium now increases rapidly, and the
central cells separate, leaving a large space within. Of the inner
cells, the second series, while not increasing in diameter,
elongate, assuming an oblong form, and from the innermost are
developed long filaments (_I_, _J_) composed of a single row of
cells, in each of which is formed a spermatozoid.

The eight outer cells are nearly triangular in outline, fitting
together by deeply indented margins, and having the oblong cells
with the attached filaments upon their inner faces.

If a ripe antheridium is crushed in a drop of water, after lying a
few minutes the spermatozoids will escape through small openings in
the side of the cells. They are much larger than any we have met
wi