Ceratopteris thalictroides , (L.) i t 5 
a single epidermal cell. Heinricher 1 has shown, in his 
researches on the origin of vegetative buds, that the bulbils 
of some of the Polypodiaceae ( Asplenium hulbiferum ) also 
arise in the same way from a single epidermal cell. I have 
been unable to verify Hofmeister’s statement in regard to 
Ceratopteris , though everything seems to point to the buds 
being developed in this manner. I have however been able 
to obtain stages in the development of the vegetative buds 
themselves, by cutting numerous series of sections through 
leaves at whose angles or lobes bulbils were present. Fig. 14 
shows a longitudinal section through the centre of a very 
young bud ; the whole bulbil is surrounded by young 
ramenta which act as a protection to the young apex and 
leaves. The apex of the bud lies in the centre ; it consists 
of a broad prominence, at the summit of which the three- 
sided apical cell is found. The apex is much broader and 
flatter in the young bud than it is in the mature stem, where 
the curious cone-shaped structure is present ; the cells too 
are smaller, but the apical cell is well marked. Sections of 
the same bud, taken either before or after the median one, 
show the beginnings of the young leaves as little protuberances 
of tissue. The whole bud itself is always situated over a vein 
of the leaf. Sections taken through a leaf bearing a some- 
what older bud show a more advanced stage in the structure 
of the apex (Fig. 15). This has become much narrower ; in 
fact, it is on a small scale a repetition of the apex of a mature 
stem which has already been given in Fig. 9. The cone- 
shaped apex is shorter and the young leaves are also on 
a smaller scale, but they arch over towards the apex in 
a similar way, and in both cases the arrangement of the cells 
is the same. 
Conclusion. 
The position of Ceratopteris amongst the Leptosporangiate 
Ferns is not altogether clear ; it has, on the whole, marked 
affinities with the Polypodiaceae, and this is more especially 
1 Heinricher, 1881, p. 115 . 
