288 Bower. — Some Normal and Abnormal 
development, and because a knowledge of the details would 
not materially increase the interest in the process, at all events 
not until the normal development of the embryo is more 
perfectly known. 
If further substantiation of the fact of apogamy in this 
species be required, it is to be found in the still more frequent 
cases represented in Figs. 55 ? 5^. these the exact converse 
is to be seen of those transitions from the sporophyte to the 
oophyte above described (Figs. 27, 30) in this plant. Here, 
without any distinct limit between them, the oophyte passes 
over into the characteristic sporophyte. This is particularly 
well shown in Fig. 55. At the base of the specimen branched 
protonemal filaments are seen attached, and the flattened 
thallus, with its marginal filaments, is quite a characteristic 
oophyte ; passing upwards, however, a vascular bundle or rib 
is gradually formed at the centre, similar in position and 
nature to that of the normal sporophytic frond, while at the 
apex a number of the characteristic conical branched hairs are 
inserted. Fig. 56 demonstrates the transition even still more 
plainly, and shows the protonema, pr> at the base bearing an 
antheridium, a . The lower portion of the flattened thallus is 
characteristically oophytic, consisting of a single layer of cells 
with marginal protonema and rhizoids ; passing upwards a 
transition is again seen to the flattened frond with midrib, 
marginal branched hairs, and characteristic apex, all of which 
characters stamp it as sporophytic. Further, a superficial 
bud, b, has been formed, having the characteristics of the 
sporophyte, and from it a vascular bundle, v.b., extends down- 
wards for a short distance into the prothallus, and finally ends 
blind. Sections were cut through this bud, and in Fig. 57, 
which is drawn from one of them, it is readily seen that 
the tissues of the sporophytic bud are continuous with 
those of the thallus, and especially that the tracheides of 
the vascular bundle, tr, pass down directly from the bud 
into the thallus. There can in these cases be no doubt as 
to the direct vegetative growth of the sporophyte from the 
oophyte. We may conclude with the utmost certainty that 
