343 
The young Bud. The apical Cell. 
Às it was pointed out before, the stipular sheath of the 
cotyledon is open in front, in agreement with B. virginianum. 
The second leaf, however, surrounds the third with an entirely 
closed sheath. The breaking up of the sheath in two distinct 
stipula seems to occur at an older stage. The arrangement of 
the leaves in the bud can be seen in Photograph 2. 
The plants investigated were too far advanced to find out 
its origin. The cell is very conspicuous and is shaped like a 
flattened, four-sided pyramid. The divisions occur chiefly in 
the two vertical planes which are situated at right angles with 
the plane of symmetr y of the young sporophyte. The divisions 
occur alternately and probably at great intervals in time. The 
position of the apical cell is not the same as in other Botrychia. 
In B. obliquum it is situated at an angle of 160 degrees with 
the horizontal, while in other Botrychia its axis is practically 
vertical. The divisions of the apical cell are shown in trans- 
verse section in Fig. 5. The form of to the cell is more like 
that found in Ophioglossum than that in Danaea. À, the apical 
cell, has given off, in a preceding period, the group of cells to 
the left of L;. This group is the beginning of the third leaf 
in which À is probably the (dividing) apical cell. At a still 
earlier period the apical cell has given off the group L», which 
is already a far advanced vascular bundle. Recently the apical 
cell has given off the group L, which will form the fourth leaf. 
The initials of the leaves are situated more or less at the leaf 
top (see Photograph 2). This is in sharp contrast with things 
as they are in B. virginianum. If we trace down the vascular 
bundle of the second leaf (Photograph 3), we find that it unites 
with the vascular bundle of the third leaf (if present) before 
Jjoining the main bundle. The most remarkable faeture in the 
whole development, up to this stage, is the complete absence 
of a stele. The vascular tissue originates only by the 
coalescence of leaf traces and the original root trace. 
