Botrychium simplex , Hitchcock . 445 
not infrequently, in sections, recently opened antheridia were encountered 
within which were found free spermatozoids. These showed quite satis- 
factorily the form of the complete spermatozoid (Fig. 10). It is a rather 
thick, somewhat flattened band, consisting of about two coils, the larger 
posterior one containing most of the nuclear substance ; the smaller anterior 
coil is made up mainly of the blepharoplast, to which are attached the cilia. 
Except for their somewhat smaller size they closely resemble those of 
B . obliquum. The antheridia are also somewhat smaller than those of the 
latter species, but, to judge from Bruchmann s figures, are larger than those 
of B. lunaria , and this is true also of the spermatozoids. 
■ i »■ V 
The Archegonium. 
The archegonium of B. simplex differs but little from that of the other 
species. As already mentioned, they are situated on the dorsal surface of 
the thallus, on either side of the antheridial ridge, but are not developed 
upon the ridge itself (Figs. 1, 2). In their earliest stages (Fig. 11) they are 
hardly distinguishable from young antheridia, but very soon their real 
nature becomes apparent. As in all the Ophioglossaceae, a basal cell is 
usually absent. The central cell becomes convex above and. grows out into 
a slender prominence which extends between the elongating neck-cells 
(Fig. 12 ; Text-fig. 2, d), and later is cut off to form the elongated neck 
canal-cell (Figs. 13, 14). The separation of the central cell and neck 
canal-cell takes place somewhat earlier in B. simplex than it does in 
B. obliquum . 
The nucleus of the canal-cell divides into two, one remaining in the 
broad basal portion, the other being near the apex (Fig. 14). In no cases 
was there any division wall seen between the two nuclei. 
As in all the other Ophioglossaceae, the presence of a ventral canal- 
cell, such as usually is found in the ferns, is difficult to demonstrate. In 
several instances there was present in the central cell of the mature 
archegonium a small body, apparently a second nucleus (Fig. 15, v). This 
nucleus, if such it was, did not stain as strongly as the egg nucleus, nor 
was there any conclusive evidence that it was the result of a division of the 
nucleus of the central cell. A similar condition was seen by the writer in 
other Ophioglossaceae, but it must, for the present, remain an open question 
whether this nucleus (?) represents the ventral canal-cell usually found in 
the fern archegonium. 
Each of the four primary neck-cells divides, by successive transverse 
walls, into about six to eight cells, of which about half extend above the 
surface of the thallus (Fig. 14). Sometimes, apparently the result of the 
obliquity of one of the first divisions in the cover-cell of the young 
archegonium, there is a certain lack of symmetry evident (see Fig. 13 ; 
Text-fig. 2, e ). 
