Some Problems of Reproduction: a Comparative Study of ...

32 MARCUS M. HARTOG.
2. Characese.
In CHARACE^; the spermatozoa are biflagellate; they are
formed by the direct evolution of the cell-bodies of short discoid
segments of long confervoid filaments; these grow by
intercalar divisions, which, perhaps, may be taken to correspond
with the ordinary gametogenic fissions of a spermatogonium.
The oosphere is formed by the enlargement of the
terminal member of a short file of cells. The cutting off of one
or three sterile basal cells (" Wendungszellen") by oblique
septa suggests the formation of one functional and one or three
arrested gametes by one or two divisions of a gametogonium.
D. ARCHEGONIATA.
This group is distinguished by the formation of the archegonium,
a cellular flask-shaped structure, with a single oosphere
occupying its belly, and a series of canal-cells its neck; the
latter degenerate to attract and bring in the spermatozoon.
1. Muscinese.
Iu the MUSCINE^; one single " initial cell" by its divisions
forms the archegonium. The earliest divisions separate off
the tissue-cells destined to form the wall and stalk of the
archegonium from the "inner cell/' which gives rise to the
oosphere and canal-cells. This inner cell divides according to
the accompanying schema (Fig. 2) ; at its bipartition are
" &c, neck canal-cells.
NH
N 3 _
N a f N=
LNM
belly canal-cell.
oosphere.
FIG. 2.—Schema of divisions of inner cell of archegonium in Muscinese.
formed two cells, a basal " central cell" and an apical " neck