Woodburn . — Spermatogenesis in certain Hepaticae. 309 
around the vesicle may be the posterior end of the blepharoplast ; however, 
this is only a conjecture and cannot be proved from the material thus far 
observed. The mature sperm, then, consists of a nuclear portion which 
makes up the main body, a blepharoplast bearing two cilia, and a small 
cytoplasmic vesicle. The evidence so far brought to light on Porella 
favours the view that the blepharoplast and cilia represent specialized cyto- 
plasmic material, which is first distinguishable in the origin of the blepharo- 
plast, as a spherical granule or body, in the cytoplasm of the sperm cell ; 
that it represents, as suggested by Mottier (’ 04 ), individualized parts of the 
kinoplasm which arise de novo in the spermogenous cells. 
As already stated, the sperm cell of Marchantia does not contain 
a centrosome-like body which has persisted throughout the last division of 
the spermogenous tissue. However, it is possible at almost any stage 
occasionally to locate granules or bodies within the cytoplasm. But it is 
only after the last division of the spermogenous cells that any body or 
granular collection can be shown to persist as an individual throughout the 
subsequent metamorphosis of the resulting sperm cell, and to become a part 
of the mature sperm. This has already been described for Porella , which, 
on account of the slow development of the sperm, gives better opportunity 
for the observance of a complete series of stages. 
Soon after the last division in Marchantia a globular or slightly elon- 
gated body appears in one point of the sperm cell (Figs. 38, 39, and 40). 
This body, as in Porella , is the beginning of the blepharoplast, and in 
appearance and subsequent behaviour is practically the same. As it pro- 
ceeds around the side of the cell, denser areas, or aggregations, of cytoplasm 
evidently contribute to its growth (Fig. 43). The direction which the ble- 
pharoplast takes around the cell is shown by comparing Figs. 41, 42, and 
43. In Fig. 41 it comes around next to the observer, while in Fig. 42 it 
goes behind the nucleus. When the pairs of sperm cells appear as shown 
in Fig. 41, the blepharoplast does not usually extend around the edge, but 
more or less next to, or away from, the observer. The mature sperm 
is quite similar to that of Porella , except that it is relatively thicker and 
shorter and not so much coiled. The cytoplasmic vesicle attached to the 
posterior end is more distinct. The greater rapidity with which the sperm 
of Marchantia develops would probably account for all of these differences. 
Just after the oblique division in Fegatella , we find the daughter nuclei 
lying in a more or less granular cytoplasm, which does not immediately 
divide (Figs. 55 and 56). The latter figure shows a number of granules in 
the cytoplasm, but it would be entirely arbitrary to select any particular one 
as the future blepharoplast, or as the body which occupied the pole of the 
last spindle. A little later, however, when the two sperm cells have 
separated, a dense body similar to the one found in M archantia or Porella, 
at first spherical then slightly elongated, appears in one angle of the cell 
Y 
