Cell Structure, Growth and Division in the Antheridia oi Polytrichum etc. 171 
of Cham. Wilson (1911) finds the blepharoplast of Pellia in the cytoplasm 
of the androcyte, at the place, occupied by a spindle pole of the preceding 
division. H. B. Humphrey (1906) first sees the blepharoplast of Fossom- 
bronia in the androcyte, as does Woodburn that of Porella. 
The Leeuwen-Reijnvaans (1907 b) think that the blepharoplast of 
Polytrichum is formed by constriction from the nucleole in the androcyte 
nucleus; and Wilson (1911) relates a similar history for Mnium and 
Atrichum. Arens (1907) finds that in Polytrichum and Mnium the bleph- 
aroplast originates in the androcyte mother cell, where it functions as a 
centrosome. 
In the Filicales, Strasburger (1892), studying Osmunda, and Thom 
(1899) and Miss R. F. Allen (1911), working on Adiantum and Aspidium, 
see the blepharoplast first in the androcyte ; but according to the results 
of Belajeff (1898, 1899) on Gymnogramme, of Shaw (1898) on Onoclea, 
and of Yamanouchi (1908) on Nephrodium, two blepharoplasts appear 
in the cytoplasm of the androcyte mother cell, he at or near the spindle 
poles during the ensuing mitosis, and finally pass into the respective 
daughter cells. 
In Marsilia , according to Shaw (1898), the two blepharoplasts found 
in the androcyte mother cell are derived from a single body which lay 
at or near the corresponding spindle pole of the final androgonial division. 
Diu'ing the penultimate androgonial division, similar bodies (“blepharo- 
plastoids”) appeared near the spindle poles; but these disappeared, and 
the bodies which by division give rise to thh functional blepharoplasts 
arose de novo. Belajeff (1899) thinks that “centrosomes” appear in all 
the antheridial divisions, lying exactly at, rather than in the neighborhood 
of, the spindle poles; and that they are probably permanent cell Organs, 
the centrosomes of each generation being derived by division from those 
of the preceding. 
Belajeff (1897 a, 1898) finds the blepharoplast of Equisetum appear- 
ing first in the androcyte, although Campbell (1895) liad described “direc- 
tive spheres” in the di vi ding androcyte mother cell. 
The blepharoplasts of Gingko and the Cycadales, as far as present 
evidence shows, arise as two distinct bodies in the cytoplasm of the body 
cell (androcyte mother cell). That the two may really result from a 
division of a single body is suggested by the fact that in Zamia (Webber, 
1897 a, 1901) they are sometimes relatively close together when first 
seen, and that in Microcycas (Caldwell, 1907) they may be in actual 
contact. No one, however, has observed the actual division of a single 
body into two. Chamberlain (1909) suggests that the blepharoplasts 
