\66 
Notes . 
occur only on archegoniophores, which are masses of meristematic 
cells. The prothallia of Schizaea , however, are completely filamentous 
throughout , not only the antheridia but also the archegonia being 
produced on filaments. 
Both kinds of sexual organs may be produced on the same pro- 
thallium, but are carried on separate branches. The archegonia are 
produced near the base of an erect filament, and occupy the position 
of lateral branches at the upper end of a cell. The cell grows out, 
forming a protuberance which is directed obliquely upwards. This 
is then cut off as an archegonium mother-cell. A second and a third 
mother-cell may be produced by the same cell. Often enough these 
are the only archegonia produced by the upright filament, but I have 
seen a second group of archegonia produced by the segment above. 
The filament which thus produces the mother-cells of the archegonia 
continues to grow upwards, and may be abundantly branched ; the cells 
are not distinguishable from those of the ordinary sterile branches. 
The mother-cell cut off in the way described gives rise to the 
whole of the archegonium. This, when mature, is flask-shaped, the 
neck is rather thick and of moderate length ; it is composed of usually 
3 tiers of cells, 4 in each tier. The cells of the terminal tier are 
longer than the others and diverge widely when the archegonium 
opens. The neck curves out below into the rather wider venter, which 
is narrowed a little to the base of attachment of the archegonium. 
It will be seen that the archegonium is remarkable amongst Ferns 
in having a free venter, and in this respect it resembles the archegonia 
of typical Bryophytes. The neck, however, is short and not of con- 
siderable length as in Bryophytes. 
Antheridia are produced in considerable numbers ; they occur 
more or less regularly on both sides of an erect filament, which may 
itself terminate in an antheridium. Rather short cells, which obviously 
correspond to branches, grow out and curve upwards. Uusually one, 
but sometimes two such cells are formed from each cell of the filament 
from the base upwards. At the end of the lateral cell a segment is 
cut off as the antheridium mother-cell. The development of the 
antheridium follows the simple type already known in Anemia ; and 
the wall which cuts off the cap-cell is nearly transverse, but it is, 
perhaps, somewhat more primitive. The mature antheridia are ovoid 
in form, the cap end being the narrower. The spermatozoids are of 
the usual type in Ferns, 
