90 
F. 0. BOWER. 
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 Osmuuda regalis. 
Angiopteris evecta. 
In the first place it may be stated that the comparatively 
few preparations of the apex of the root of Angiopteris 
which I have made, confirm the results of Schwendener’s in- 
vestigation. It would be interesting to know, as the result of 
a careful and detailed study, whether, under any circumstances, 
wedge-shaped initial cells, similar to those occasionally seen in 
Todea barbara, are to be found in Angiopteris. The 
descriptions of Russow 1 and of Holle 2 may have had some foun- 
dation in irregularities of this sort. In view of the incon- 
stancy of form of the initial cells in Osmunda and Todea it 
would be rash to assert that pyramidal initial cells never occur 
in the Marattiacese, though cells of truncated pyramidal 
form appear to be typical in the roots of these plants. 
Since the origin of the lateral roots of the Marattiacese 
has not hitherto been described, and as the material for this 
work was at hand, I have made some observations on this point. 
The lateral root of Angiopteris evecta takes its origin, 
as in other Ferns, from a single cell of the endodermis, situated 
opposite one of the numerous xylem groups (fig. 30). This 
rhizogenic cell enlarges, and divides repeatedly by walls per- 
pendicular to the outer surface of the main root into a number 
of oblong cells, of which four lying at the centre of the group 
assume the properties of initial cells. In those cases which 
I have had under observation the walls of segmentation of the 
rhizogenic cell are not inclined to one another, and the initial 
cells are not pyramidal, but always oblong. The mode of 
further subdivision of the cells thus produced, and the position 
of the initial cells with their segments are clearly seen in fig. 31, 
taken from a more advanced lateral root than fig. 30. Fig. 32 
1 ‘ Yergl. Unters.,’ pp. 107 — 109. 
2 ‘ Bot. Zeit.,’ 1875, p. 301. 
