PTERIDOPHYTES 
129 
outermost one of this row of cells, they are called primary neck cell, 
central cell, and basal cell. The primary neck cell, by successive divi- 
sions, develops a neck consisting of several tiers of cells (figs. 284- 
286), with four cells in each tier. The central cell develops the axial 
row as follows : the first transverse division results in the primary 
neck canal cell (the outer one) 
and the primary ventral cell 
(the inner one, fig. 285). By 
successive transverse divi- 
sions, the primary neck canal 
cell produces a variable 
FIG. 277. Garnet o- 
phyte (g) of Lycopodium 
annotinum (entirely tuber- 
ous and subterranean), 
bearing a young sporo- 
phyte (s, /); the ground 
line is shown. After 
BRUCHMANN. 
FIGS. 278-282. Antheridium of Lycopodium 
davatum: 278, to the right a young antheridium 
after the first division (periclinal) of the super- 
ficial initial cell; to the left a much older 
antheridium; 279, young antheridium after di- 
vision of primary wall cell and primary sperma- 
togenous cell; 280, further development of 
spermatogenous tissue; 281, nearly mature an- 
theridium, showing the wall (consisting of one 
layer of cells) and the mass of spermatogenous 
cells; 282, two sperms, showing the biciliate 
character. After BRUCHMANN. 
number of neck canal cells (fig. 286) ; in some cases four to six, but 
in other cases as many as thirteen have been observed. This ex- 
traordinarily large number of neck canal cells is regarded as a low 
character, since a steady decrease in the number of neck canal cells 
