448 Wilson. — Spermatogenesis in the Bryophyta . 
the spermatogenesis of Chara would be of considerable interest in this 
respect. 
The present writer is in agreement with Ikeno concerning the phylo- 
genetic origin of the blepharoplast from the centrosome in the great majority 
of plants. This view is considerably strengthened by a comparison of its 
origin in animals, where in the great majority of cases it is identical with 
or directly derived from the centrosome. 
The term blepharoplast was introduced by Webber (73) in 1897, who 
defines it (footnote, p. 30) as { the cilia-forming organ of the spermatogenous 
cells of Zamia and Ginkgo , which so nearly resembles a centrosome or 
ceiitrosphere ’. This investigator states ‘ there would seem to be no possible 
doubt ’ that the subsequent formation of the cilia-bearing band in Zamia is 
organized at the expense of and by the granules of the blepharoplast. The 
production of a thread or band from the blepharoplast has also been described 
in Onoclea and Marsilea by Shaw (57) and by Yamanouchi (76) in Nephro - 
dium. Until the present, however, no thread-like structure produced in 
connexion with the blepharoplast has been definitely described in the 
Bryophyta. Ikeno (32) in Marchantia describes the slight elongation of 
the blepharoplast, but states that the latter becomes connected with the 
nucleus by a ‘ cytoplasmatischer Vorsatz’, which grows, not from the 
blepharoplast, but towards it. J. and W. Docters van Leeuwen-Reijnvaan 
(41) state that a similar band is found in Polytrichum , in this case growing 
from the blepharoplast towards the nucleus. Humphrey (30) in Fossom - 
bronia describes the slight elongation of the blepharoplast, but states that 
the connexion with the nucleus is completed partly by the cytoplasm and 
partly by the elongated ‘ Nebenkorper ’. Bolleter (13) gives a somewhat 
similar account in the case of Fegatella. 
A slight elongation of the blepharoplast has been described in Mnium 
in this investigation, but the thread is quite distinct from this and is present 
in addition to it. The elongation takes place towards the anterior part of 
the spermatid, while the thread is produced in an opposite direction. The 
thread has been described in Mnium hornum , Atrichum undulatum , and 
Pellia epiphylla , and there is no doubt that it is homologous in these three 
species. In each of these plants the nucleus elongates right up to the 
blepharoplast, and consequently no cytoplasmic material is intercalated 
between the two. In this respect these observations agree more closely 
with the accounts of spermatozoid formation in Pellia given by Buchtien 
(15) and Guignard (26 a) than with the more recent accounts given of this 
process in the Hepaticae. With the exception of the blepharoplast and 
the thread-like structure, the whole of the body of the spermatozoid is pro- 
duced from the nucleus. A thread-like structure closely resembling that 
found in the two mosses and in Pellia has been described by Mottier (47) 
in the spermatid of Chara. In this case, however, the thread does not 
