449 
Wilson.— Spermatogenesis in the Bryophyta . 
grow out in connexion with a blepharoplast, but is produced by a differentia- 
tion of the cell membrane. At present it must be left an open question 
whether this thread in Char a is homologous with that described in the 
Bryophyta . 
It has already been pointed out that the origin of the thread-like body 
in the plants examined has not been definitely determined. Two methods 
of formation are possible : — 
1. The thread is formed by an extension of the blepharoplast sub- 
stance, and forms a part of the latter body. 
2 . It arises by a differentiation of the plasma membrane, and is 
distinct from the blepharoplast. 
If the first view is accepted, it appears that elongation of the blepharo- 
plast goes on in two directions in Mnium , towards the anterior part of the 
spermatid forming a short bar-like structure, and in the opposite direction 
producing the thread. Such a process has, however, not been previously 
described in connexion with the blepharoplast. On the second assumption 
the thread is a structure distinct from the blepharoplast. In this case the 
thread is not homologous with the blepharoplasts described in the Bryo- 
phyta, Pteridophyta, and zoidogamous Gymnosperms. As additional 
evidence for this, it may be pointed out that the thread has apparently no 
direct connexion with the cilia. Further investigation is necessary before 
any decision can be arrived at regarding this matter. 
The processes involved in the actual production of the spermatazoid in 
Pellia and the two masses examined are very similar, as is shown by 
a comparison of Fig. 57 of Atrichnm and Fig. 79 of Pellia (PI. XXXVIII). 
Subsequent to the production of the thread and limosphere, the changes 
which take place in Pellia and Atrichum are almost identical. 
In many of the cases in which the spermatogenesis of plants has been 
carefully investigated, one or more chromatic bodies in addition to the 
blepharoplast and nucleus have been discovered in the spermatid. This 
has been emphasized by Ikeno in his description of Marchantia. In the 
spermatids of this plant he described the occurrence of a fairly large 
spherical body which takes up the nuclear stain freely. He refers to this 
as the chromatoid ‘Nebenkorper’, and suggests that it is homologous to the 
body described by Meves (46) under this name in the spermatids of several 
animals. The origin of this body was not determined, and it soon dis- 
appears, taking no direct part in the formation of the spermatozoid. He 
considers the ‘ Nebenkorper ’ is homologous with the blepharoplastoids de- 
scribed by Shaw (57) in Marsilea , and the ‘corps spherique ' found by 
Hirasd (27) in Ginkgo . It is interesting to note these bodies also are stated 
to take no direct part in the formation of the spermatozoid. A similar 
body was subsequently described by Bolleter (13) in Fegatella , and by 
Humphrey (30) in Fossombronia , but in the latter plant it is stated that the 
