161 



are always four nearly equal inner cells resulting (Fig. 72). 

 The third set of walls is vertical, and the next in some cases 

 at least (Fig. 73) is in the same direction. This is not true, how- 

 ever, of the deeper and narrower type of antheridium (Fig. 68). 

 Further divisions continue until the number of spermatocytes 

 is very large. The fully developed mass of spermatocytes is 

 plainly visible to the naked eye, and in O. pendulum may 

 reach a diamater of more than 325 ^. More than 250 cells 

 can be counted in a single section of a large antheridium, and 

 this would mean that there ai-e several thousand in the whole 

 antheridium, — probably more than in any other Pteridophyte. 

 In (X moluccanum (Figs. 64 — 65) the number is much smaller. 

 The antheridium of (). vulgatum appears to be intermediate in 

 size between that of 0. moluccanum and (K pendulum.. The 

 nucleoli which are conspicuous in the younger cells (Figs. 

 63 — 72) become less evident in the older ones. According to 

 Mettenius (loc. cit. Figs. 18, 19) the outer wall of the anthe- 

 ridium is composed of two layers of cells, but Lang and 

 Bruchmann both found that the. central part of this outer wall 

 is but one cell in thickness. The cover really is composed only 

 in part of the cells derived from the original cover cell, as 

 the mass of spermatocytes extends laterally far beyond the 

 limits of the cover cell, this being especially the case where 

 the mother cell is deep and narrow. 



The first wall to be formed in the cover cell is nearly 

 median and vertical (Fig. 72) and this is followed by a second 

 wall which intersects it, as well as one of the lateral walls of 

 the primary cover cell, so as to include a nearly triangular 

 cell (Fig. 76). In the latter there are formed later, as both 

 Bruchmann and Lang showed, a varying number of segments 

 arranged spirally in the fashion of the segments of a three- 

 sided apical cell (Fig. 78). The same thing occurs in Lycopo- 

 dium (TREUB-Etudes sur les Lycopodiacees, II, Annates du 

 Jardin Botanique de Buitenzorg. V, pi. XX, Fig. 6). The 

 Marattiaceae and Equisetum (Campbell, loc. cit., 1st edit. 

 Fig. 221). The last formed triangular cell is the opercular 



