Developments of the Oophyte in Trichomanes . 297 
having the shape of half of a biconvex lens, from which seg- 
ments are successively cut off ; but I am not in a position 
to state that this is constantly the case, and it must be 
remembered that, even if it were, the development in this 
apogamous species is not normal. 
In TV. pyxidiferum , in which the antheridia develop nor- 
mally, a similar appearance is seen on external observation 
of the antheridium (Fig. 9, E, F), but optical sections point 
to a succession of cell-divisions (Fig. 9, A, B, C), which does 
not support the idea of a wedge-shaped apical cell. It may 
further be noted that at least one of Cramer’s drawings of 
antheridia 1 indicates the possible presence of an apical cell, 
while an alternation of segments cut off at the base of the 
antheridium has also been observed by Goebel 2 in Hymeno - 
phyllum. Thus, though the development of the antheridium 
does not appear to be perfectly constant in these plants, there 
are peculiar cell-divisions in it which do not coincide with 
those customary for Ferns. If an apical cell were actually 
present (and it must remain for further observations to decide 
this) it might be recognised as a character approaching that 
of the true Mosses ; but at present this point cannot be closely 
pressed. Among the Ferns the succession of segments in the 
antheridium of Osmunda as described by Kny 3 approaches 
more nearly to that above described than is the case with those 
forms in which the funnel-shaped wall exists. 
The description above given shows that the massive growths 
(archegoniophores) on which the archegonia are inserted do not 
conform to any strict type of origin, structure, or arrangement 
of cells in TV. pyxidiferum. The view that the leafy 4 Moss 
plant’ may have arisen from an outgrowth of the protonema, 
such as the archegoniophore of Trichomanes , has been sug- 
gested by Goebel 4 , and in the above observations I see nothing 
to cast doubt upon this ; it is to be remarked, however, that, if 
we accept Goebel’s proposed scheme, the specimen shown in 
Fig. 13 is a nearer approach than any hitherto described to 
1 . c. Taf. i. Fig. 9 an. 
Prings. Jahrb. 1872. 
2 1 . c. Taf. viii. Fig. 82. 
* 1. c. pp. in, 1 1 2. 
