1 74 Farmer and Dig by. — Studies in Apospory and 
We have studied the process of fertilization in the common Male Fern 
(Fig. 35) for purposes of comparison, and it is easily seen that the similarity 
between the oosphere in our Scolopendrium and that of a normal Fern ends as 
maturity approaches. Before the neck of the archegonium opens, in many 
cases at any rate, the egg becomes surrounded with a membrane, and the 
possibility of fertilization is thus definitely excluded. It is very common in 
old degenerating archegonia to find the oospheres thus enclosed in a proper 
membrane, whilst otherwise exhibiting signs of disintegration. A frequent 
symptom of approaching death is visible in a more or less complete fragmenta- 
tion of the nucleus. We had observed in otherwise healthy and compara- 
tively young oospheres (Fig. 36), which had not yet become surrounded 
with membranes, that occasionally there were two well-defined and large 
nucleoli, and that the linin was clearly grouped with reference to these 
two centres. In other cases it appeared as if amitosis were going to 
supervene, for the nucleus had become correspondingly two-lobed, con- 
nexion by means of a very narrow isthmus being, however, preserved. 
But we are convinced that these appearances are signs of approaching 
senility, and that they do not represent stages in the first segmentation 
of the egg. Of course, the definite proof of this can only be given when 
the first division is actually seen, and we have as yet not succeeded in 
obtaining preparations to illustrate this, but the weight of probability is 
strongly in favour of an ordinary mitosis being associated with the first, as 
it is with the later divisions of the embryo. 
The mode of segmentation of the embryo, more than one of which 
may be formed from one prothallium, closely follows that already described 
in Ath. Filix-foemina var. clarissima ) Bolton. The first wall, the basal, 
separates the epibasal from the hypobasal half, and the former is nearly 
hemispherical in shape, whilst the latter is more conical. In the epibasal half 
the median and transverse walls arise consecutively, whilst in the hypobasal 
portion the first wall is formed in a plane parallel to that of the basal one. 
Subsequent divisions rapidly arise, and the parts of the young embryo 
become recognizable. There is a distinct foot, but it is not easy to 
distinguish its limits from the cells of the wall of the inner part of the 
archegonium, which divide freely and become densely filled with food 
materials (Fig. 37). The young sporophyte grows rapidly, and, as is so 
common with many aposporous ferns, the first-formed leaves show a marked 
tendency to produce prothallial outgrowths when the plants are cultivated 
under hurried conditions. 
It is instructive to note that the prothallium of this variety behaves 
very differently from those of the common species of Hart’s-tongue, when 
it assumes an apogamous development. In the first place, as described by 
Lang, 1 the embryo in the latter Fern arises from a * cylindrical process,’ 
1 Lang, Phil. Trans., vol. 190, p. 196. 
