SOME PROBLEMS OF REPRODUCTION. 33 
canal-cell,’ Thelatter elongates with the neck of the growing 
archegonium which it occupies and fills, and by repeated 
bipartitions forms a file of cells (a multiple of four) which are 
also termed “neck canal-cells.”” The proximal cell (central 
cell) occupies the belly of the archegonium, enlarging with it, 
but undergoing no further division till its maturity. Then 
this central cell divides into two, the lower rounding off as 
the oosphere, the upper undergoing mucous degeneration 
like the neck canal-cells, and termed the “ belly canal-cell.” 
Sometimes these two sister-cells are equal, but usually the 
belly-cell is much smaller. Obviously both are gametes, the 
former functional, the latter degenerate. 
The next question that arises is this:—What are we to re- 
gard as the “oogonium”—the central cell, the inner cell, 
or the initial cell of the archegonium? The divisions of the 
last are too closely allied to those which form tissue-cells 
elsewhere ; and of this nature are the majority of its brood- 
cells forming the wall of the oogonium, so that it would be 
rather strained to call the initial cell a gametogonium. The 
second alternative would seem most natural: to regard the 
inner cell asa gametogonium, and the neck canal-cells as 
degraded gametes (or rather their offspring). For though the 
growth of these is concurrent with that of the cells of the 
neck and accompanied by numerous divisions, yet the hori- 
zontal septa are not coplanar with those of the neck wall, and do 
not complete with these the schema of orthogonal trajectories, 
which they should do if they belonged to the same system 
of tissue-cells ; their number is always a multiple of four; and 
while the cells forming the oogonial wall have a prolonged 
life, that of the canal-cells is limited, as in most gametes. 
Again, the antheridium is formed from a single initial cell similar 
to that of the archegonium, and similar divisions mark off its 
wall-cells from a single central cell. The latter forms a 
complex of cubical spermatocytes only, by repeated bipartition, 
the cell-walls intersecting at right angles ; and the cell body 
of each spermatocyte is converted into a biflagellate sperma- 
tozoon, a small portion of the cytoplast remaining unutilised 
VOL. XXXIII, PART I.—NEW SER. Cc 
