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Charles E. Allen 
been previously published upon the cytology of members of this group. 
Descriptions of the development and structure of the antherozoids will 
not, however, be cited here, but will be eonsidered in a paper now in 
preparation on the spermatogenesis of Polytrichum. 
After the deseription by Hedwig (1782, 1784) of the male and female 
organs of mosses (identified by him respectively as “stamens” and “pistils” 
because of their similarity in appearance to the organs so named in seed 
plants), no material advance was made in the study of either structure 
until the discovery by Unger (1834) of the motile antherozoids of Sphag- 
num capillifolium. In the summer, when the “anthers” are still immature 
though of nearly full size, Unger (1838« — h) found that their interior 
fluid eontains only isolated vesicles; but in the autumn, when the anthers 
are mature and the fluid attains its greatest density, it is filled with count- 
less small moving animal-like bodies. 
Meyen (1839) describes the “pollen mass” in the not quite mature 
anther as consisting of a homogeneous, colorless slime, and, imbedded 
in this, numerous greenish, spherical granules. Influenced by Schleiden’s 
doctrine of cell formation, Meyen concludes that these granules grow 
and develop into delicate cells, each eontaining a “Samenthierchen”. 
The interior of the antheridium, according to Schleiden (1843), 
consists, at an early stage, of a large “central cell”; this cell later eontains 
free cytoblasts, and finally beeomes filled with a thin-walled tissue, in 
each of whose cells a spiral filament develops. A large cell filling the in- 
terior of the antheridium is described also by Mettenius (1845); this cell 
encloses smaller cells, witliin which in turn the antherozoids are formed. 
The antheridium is described by Hofmeister (1851) as eontaining 
a great number of small cells, in each of which, and within a lens-shaped 
vesiele, a spirally coiled filament is formed. 
Schacht (1852) says that the antheridia of the higher cryptogams 
contain mother cells, each of which, by direct division of its primordial 
utricle, forms round free cells; within each of the latter a spiral band is 
developed. 
Schimper (1858) finds that the antheridium of Sphagnum , as the 
result of a series of divisions, eontains many small cubical cells. He notes 
a separable cuticular layer covering the outside of the antheridium, which 
he thinks may have suggested the “central cell” of Schleiden and Met- 
tenius. MTiat was perhaps this same layer had been seen by Unger 
(1838«), but he had thought that it lav within, instead of without, the 
cellular wall of the antheridium. 
