169 
Apogamy in Ferns. 
The antherozoids seem generally to be attracted as far as the ventral 
canal cell, and only accidentally to reach the actual cavity of the venter 
(Figs. 28, 29), though occasionally as many as three or four were seen there. 
They do not enter the egg, which is surrounded by a delicate pellicle. The 
antherozoids soon die after they reach the venter. 
Whether or not any stimulus to further development on the part of the 
oosphere is given by their proximity must be left undecided. The two 
kinds of sexual organs are produced in such large numbers that it has not 
been practicable to isolate prothallia-bearing archegonia, but the indirect as 
well as the negative evidence against impregnation seems to us to be con- 
clusive. Not only have we not seen anything to indicate the entrance of an 
antherozoid into an egg, but the absence of any increase in the chromo- 
somes in the embryo, as compared with the prothallial cells, would seem to 
preclude the possibility of any act of fertilization having occurred. As 
in the foregoing variety, no migrations of the nuclei from one prothallial 
cell to another were seen. 
The embryo in this variety, so far as our own material is concerned, 
invariably arises from the oosphere (Fig. 29). In this respect it stands 
in sharp contrast to that of the preceding variety, in which it as constantly 
originates from prothallial tissue, and never directly from the egg. The 
first divisions are somewhat inconstant, but the basal wall, parallel to the 
long axis of the archegonium, is the first to appear. The two halves of the 
embryo then segment differently, and this is perhaps to be correlated with 
the blunter form of the anterior and the more pointed character of the 
posterior half of the embryo at this stage. In the epibasal half (Fig. 30), 
the median wall almost always precedes the appearance of the transversal 
wall, but these two walls cut up the epibasal half of the embryo into the 
usual four octants. In the hypobasal half of the embryo the first division- 
wall is most commonly parallel to the basal wall, and thus in longitudinal 
sections the embryo as a whole appears to consist of a row of these cells 
(Fig. 29). Then each of the two cells in the hypobasal region is divided by 
a wall most often situated in the median plane. It may happen, however, 
that the transversal wall appears instead of the median, though this appears 
to be exceptional. 
We did not attempt to follow out the further development of the 
embryo in detail. The process very closely resembles that of an ordinary 
Fern. A tolerably well-developed foot is formed, though it is smaller than 
the corresponding organ in the typical forms. The cells surrounding the 
base of the archegonial cavity become filled with temporary reserve 
materials which are ultimately absorbed, on behalf of the growing embryo, 
by the cells of the foot. 
As in the preceding variety, there is a very regular and characteristic 
difference in the average size of the cells and nuclei as compared with those 
