656 Campbell . — The Structure and Affinities of 
suspensor is derived from the original suspensor cell, and how much, if any, 
is derived from the hypobasal cell, must for the present remain doubtful. 
The embryo, except for the suspensor, is much like that of Angiopteris 
at the same stage. It is much flattened, and near the centre of the upper 
surface could be seen a cell which may possibly represent the stem-initial 
(Fig. 38). The root-initial had not yet been differentiated, but it probably 
arises from the central region of the embryo, as it does in the other 
Marattiaceae. 
PL XLVII, Figs. 40-42 show three transverse sections of an embryo 
in which the root is just differentiated. Fig. 42 passes through the foot, 
and shows part of the thick lateral suspensor (sns.). Fig. 41 is a nearly 
median section, and passes through the root-initial (r.), from which the first 
segment has been cut off. As in the other Marattiaceae, the root is a strictly 
endogenous structure, the initial cell arising near the centre of the embryo, 
probably from the lower part of the epibasal region. Fig. 40 shows the 
upper surface of the embryo. The large cell (.?/.) perhaps is the apical cell 
of the stem, but this is not certain. 
No large embryos were found, the youngest sporophytes obtained 
having the cotyledon well developed and the root penetrating the ground. 
Sections of such sporophytes (PI. XLVII, Fig. 43) show the same arrange- 
ment of the organs as in other Marattiaceae. 1 As is usual in these Ferns, the 
young sporophyte has the axis of the cotyledon coincident with that of the 
root, a common vascular bundle extending without interruption from 
the leaf into the root. The stem-apex is inconspicuous and consists of 
a shallow group of large cells, so much alike, that it is not easy to distinguish 
the actual apical cell. In PI. XLVII, Fig. 44, it is probable that the large 
cell (st.) is the initial cell of the stem-apex, but this is not certain. In the 
few cases found, the initial cell in longitudinal section appeared oblong 
in form. 
The second leaf makes its appearance very early, and there is soon 
discernible a strand of procambium cells, representing the second leaf-trace, 
connecting the leaf rudiment with the common bundle of the primary leaf 
and root. As in the other Marattiaceae there is no evidence at this stage 
of any true cauline bundle or stele. 2 The cotyledon, like that of Angiopteris , 
shows a good deal of variation. It is usually fan-shaped, with a more or 
less marked dichotomous venation, but there is frequently a more or less 
distinct midrib, and sometimes the cotyledon is almost lanceolate in outline, 
with a conspicuous midrib (PI. XLVI, Fig. 6) and lateral veins. 
Text-fig. 1 shows a series of cross-sections from a young sporophyte 
in which the second leaf was just discernible. The stem-apex is occupied 
by a group of meristematic cells, among which it is not easy to recognize 
with certainty a single initial cell. 
1 See Campbell, loc. cit. 
2 See Campbell, loc. cit. 
