204 Atkinson. — A Monograph of the 
shows the relation of the generative filaments to the anthe- 
ridia in the subgenus Sacheria. Fig. 32 shows the same in 
the subgenus Lemanea . The terminal cells bear a resemblance 
in form to those of the medullary and intermediate layers ; 
but they are richer in coloring matter and protoplasm. Fig. 
35 represents a longitudinal section through an antherid-zone 
during the development of the specialized cells which bear 
antheridia ; b b f are the last cells of the generative filament, 
which retain their form ; c c are produced from b b' ; c c in 
turn abjoint still smaller cells, which bear elongated columnar 
cells, d d. These last are the antheridiophores. Each one 
produces by growth at its outer extremity, usually one anthe- 
ridium, sometimes two antheridia. It must be understood 
that in making the section other cells above and below were 
cut away, so that only a plane remains, while a cone-shaped 
group was developed from the ends of the cells next to the 
generative filaments. The columnar cells d d, the oval cells 
c c, and the smaller ones between, are very rich in coloring 
matter. At the time of anthesis, when the sexual shoot is 
translucent in other places, it is clouded in the antherid-zone, 
because of the presence of this rich coloring matter. Fig. 44 
represents the clouded appearance of the cells which bear the 
antheridia. The antheridia are oblong, thin-walled sacs ; 
each one contains an oblong, hyaline, non-motile spermatozoid, 
8 ju-10 ijl long, and about one third as wide. 
The arrangement of the antheridia into variously shaped 
groups or patches bears a direct relation to the branching of 
the generative filaments. The affinities here show that the 
terminal branching of the generative filaments in the subgenus 
Lemanea is more profuse than in the subgenus Sacheria. Fig. 
44, Lemanea australis , shows how all of the generative fila- 
ments meet, by their terminal branches, in a ring on the 
inner periphery of the wall, and there form a continuous 
antheridial ring, which is characteristic of the subgenus 
Lemanea. Where the ring is broken the branching is less 
profuse. Where the ring is irregular the terminations do not 
meet those of the adjacent segment evenly. In the subgenus 
