144 
Campbell . — The Garnet ophyte and 
angles to the first one. The later divisions do not show any definite order, 
and the number of spermatocytes formed varies a good deal. 
The material was not particularly favourable for a study of spermato- 
genesis, and, as there was nothing to indicate any deviation from what has 
been observed in other Ophioglossaceae, no attempt was made to study it in 
detail. 
It may be assumed that, as in other pteridophytes, the body of the 
spermatozoid is derived mainly from the nucleus of the spermatocyte. The 
nucleus becomes an almost homogeneous, thickened band tapering towards 
the anterior end of the spermatozoid. In the later stages, the slender coiled 
blepharoblast, from which the numerous cilia arise, can be readily demon- 
strated, but the earlier stages of the blepharoblast were not studied. As 
the fully developed spermatozoid closely resembles that of B. virginianum , 
it may be assumed that the early stages of development are the same. 
The mature spermatozoid (Fig. 18) is nearly twice as large as that of 
B. virginianum , but otherwise is very similar. In its large size it recalls 
Ophioglossum } The walls of the ripe sperm cells stain very strongly? 
indicating that there has been a development of mucilaginous matter in the 
walls. These walls stain especially strongly when treated with Bismarck 
brown. 
Of course it was not possible to study living spermatozoids, but a good 
many of the sections showed recently opened antheridia which contained 
some of the free spermatozoids which were pretty well fixed. 
The earlier archegonia are formed in a line on either side of the anther- 
id ial ridge, but later they may develop behind the growing-point of the 
gametophyte at almost any part of the dorsal surface. 
The earliest stages are hardly distinguishable from very young 
antheridia (Figs. 19, 20). The first wall is transverse and cuts off an outer 
from an inner cell. The former, by further divisions, forms the neck cells, 
the latter the egg and canal cells. As a rule no basal cell is present, but 
sometimes it looks as if such a cell might occasionally be formed. 
The cover cell is usually rather shallow, but sometimes may equal 
in depth the inner cell (Text-fig. 3, A). As in all ferns, the first divisions in 
the cover cell are intersecting median vertical walls determining the four 
rows of neck cells. 
By the time the first divisions in the cover cell are completed, the 
inner cell begins to grow up between the four neck cells, and as these 
elongate and undergo further divisions, there is formed a slender extension 
of the central cell which later is cut off from it as the neck canal cell. The 
separation of the canal cell from the central cell occurs at an unusually late 
period in B. obliquum when compared with the other Ophioglossaceae. 
Each of the four primary neck cells divides by a series of oblique 
1 Campbell : loc. cit. 
