APEX OF THE ROOT OF OSMUNDIA AND TODEA. 89 
the Marattiacise, but rather show the great irregularity of 
the roots of Osmunda. 1 
Todea barbara. 
For comparison with Osmunda regalis the roots of 
Todea barbara 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, such as 
that seen in fig. 23, in which case it appears uncertain whether 
the meristem is referable to three or four initial cells. In a 
majority of the roots observed it is clearly referable to four 
initial cells (fig. 24), separated from one another by the four 
principal walls ( p ). 2 The meristem in this case appears closely 
similar to that described by Schwendener in the Marattiacese. 
Longitudinal sections, however, do not show so close a cor- 
respondence to the structure described by him in this group. 
Pyramidal cells are not unfrequently to be found, as in fig. 25 } 
where two (x) are to be seen in a similar relative position to 
those in the root of Osmunda represented in fig. 16. In 
other examples, however, the initial cells have the form of 
truncated pyramids, as in fig. 26, segments being cut off from 
the truncated apex, as well as from the sides and base. This 
arrangement probably corresponds to that shown in transverse 
section in fig. 24. 
The origin of the lateral roots was also observed in this 
plant. As before, in Osmunda, the root originates from a 
single cell of the endodermis, situated opposite one of the 
groups of xylem. A few irregular divisions may also be traced 
in adjoining cells of the cortex, but I was unable to ascertain 
whether these cells take any active part in the formation of the 
root-cap. Occasionally the divisions of the rhizogenic cell are 
somewhat irregular, as in fig. 27, but usually the divisions are 
symmetrical, as in figs. 28, 29. These two figures, however, 
1 This subject will be more fully discussed below. 
3 I see no objection to using this term again here, though there are four of 
them. 
