3 1 4 Bower . — The comparative examination of the 
single pyramidal cell narrower than that of Naegeli’s type, and 
corresponding in many points to that of the older root shown 
in Fig. 6 . 
For comparison with Osmunda regalis the roots of Todea 
barbara 1 were investigated with the following results : Of a 
number of apices from which transverse sections were cut 
not one showed a clearly marked single apical cell. Some, 
however, showed somewhat irregular arrangements, and in 
some of these it appeared uncertain whether the meristem be 
referable to three or to four initial cells. In a majority of the 
roots observed it is clearly referable to four initial cells 
(Fig. 12), separated from one another by the four principal 
walls (p). The meristem in this case appears closely similar 
to that described by Schwendener in the Marattiaceae. 
Longitudinal sections, however, do not show so close a corre- 
spondence to the structure described by him in this group. 
Pyramidal cells are not unfrequently to be found, as in Fig. 13, 
where two are seen (x, x). In other examples, however, the 
initial cells have the form of truncated pyramids, as in Fig. 14, 
segments being cut off from the truncated apex, as well as 
from the sides and base. This arrangement probably corre- 
sponds to that shown in transverse section in Fig. 12. 
The origin of the lateral roots was also observed in this 
plant. The root originates from a single cell of the endo- 
dermis, situated opposite one of the groups of xylem. Usually 
the divisions are symmetrical, as in Figs. 15, 16, and these 
two figures show that from the very first the initial cells of 
the young root are subject to a certain variation of form, 
being in some cases pyramidal, in others truncated. Thus, 
in this respect again, Todea barbara resembles Osmunda 
regalis. 
The foregoing description of the structure of the apical 
meristem of the roots of Osmunda and Todea shows that 
there is no such strict uniformity in these plants as is found 
in the meristem of the roots of typically leptosporangiate 
1 See postscript, p. 388. 
