2 86 Alien. — The Spermatogenesis of Poly trichum juniper inum . 
Walker’s (1913) figures of the developing androcytes of P oly trichum 
formosum come much nearer to giving a complete history of the limosphere 
than do those of any previous writer. In his description, unfortunately, 
Walker has confused the anterior and posterior ends of the blepharoplast 
and of the nucleus, and has not altogether succeeded in distinguishing 
artefact from normality. 
Woodburn (1915) shows the limosphere plainly in several of his figures 
of stages in the spermatogenesis of Mnium. He seems, however, to be quite 
uncertain as to the permanence, or even the identity in different cases, of the 
body that he figures. 
The bean-shaped ‘amylaceous mass’, described by Guignard (1889) in 
the androcyte of Sphagnum , which persists in the cytoplasmic vesicle 
attached to the posterior end of the antherozoid. suggests in its behaviour 
an analogy at least to the limosphere of Polytrichum. Campbell (1887) had 
seen the same body in the vesicle of the antherozoid of Sphagnum , and had 
concluded from its reactions with iodine that it was starch. Still earlier, 
Roze (1864) had made a similar observation. It remains for present-day 
cytological methods to determine how closely Sphagnum agrees, in this 
feature of the history of its androcyte, with the Bryales that have been 
investigated. In this connexion it may be a pertinent fact that several 
writers have described starch grains as present in some numbers in the 
cytoplasmic vesicles of the antherozoids of Pteridophytes. 
The ‘ Nebenkern ’ found by Yamanouchi (1908) in the androcyte of 
N ephrodium might be thought to correspond either to the limosphere or to 
the percnosome. Its small size during most of the history and its variable 
position within the androcyte make its identification with the latter body 
seem more probable ; but its larger size in the later stages of spermato- 
genesis and its persistence in the cytoplasmic vesicle that is attached to 
the posterior end of the mature antherozoid suggest a resemblance to the 
limosphere. It is possible that the very small Nebenkern of the early part 
of this history and the somewhat larger body observed in later stages are 
not, as Yamanouchi evidently believes, identical. There is even greater 
uncertainty as to the identity of a body described by Thom (1899) as 
a ‘ blepharoplast ’ or ‘ N ebenkern ’ in the androcytes of Aspidium and 
Adiantum . The fact that he finds this body still present and unchanged in 
form after the elongation of the nucleus has begun seems to indicate that he 
is dealing, not with the blepharoplast as he supposes, but with another body 
which probably corresponds to Yamanouchi’s 'Nebenkern ' . 
The two large, spherical cytoplasmic bodies which Hirasd (1898) first 
observed in the body cell (androcyte mother-cell) of Ginkgo are also possibly 
homologous with the limosphere. In the division of the mother-cell, one of 
these bodies passes into each androcyte, where it persists throughout the 
development of the antherozoid, and is visible in the cytoplasm of the latter 
