145 
Embryo of Botrychium ob lignum, Miihl. 
transverse walls into about six. Of these the upper half, approximately, 
extend above the surface of the gametophyte, the others lying below it 
(Text-fig. 3). 
The nucleus of the neck canal cell later divides into two, but no cases 
were seen where a division wall had been formed, as is not unusual in 
Ophioglossum pendulum , but has not yet been demonstrated in Botrychium. 
The presence of a ventral canal cell could not be demonstrated satis- 
Text-fig. 3. A. Young archegonium. x 320. B-D. Older archegonia. x 2-jO. e. Mature 
archegonium, showing apparent ventral canal cell, v. x 240. F. Open, but unfertilized, arche- 
gonium. x 240. 
factorily, although several preparations were secured which indicated that 
a ventral canal cell — or at least a nucleus representing this — was present. 
In Fig. 22 there is shown one such case, where in close contact with the 
nucleus of the central cell a second smaller nucleus is visible and a zone of 
somewhat denser cytoplasm, but no evident cell wall. In Text-fig. 3, E, 
another example is shown. In this instance there was apparently a small 
cell between the egg and the neck canal cell. The nucleus of this cell (?) 
was small and not very distinct. 
A similar difficulty in demonstrating a ventral canal cell has been 
experienced by the writer in his investigations of other Ophioglossaceae. 
It seems probable that in all of these the ventral canal cell is cut off very 
L 3 
