248 Mottier. — Development of the Spermatozoid in Chara. 
(Figs. 2, 3). Observed from the end they are, therefore, circular in outline, 
and in longitudinal section somewhat rectangular. Before differentiation 
begins, the nucleus is spherical or elliptical, and lies near the middle of the 
cell. The diameter of the nucleus is almost as great as the length of the 
cell, so that there appears to be room enough only between nuclear 
membrane and either transverse wall for the plasma-membrane. The 
chromatin is arranged in the form of a somewhat regular but interrupted 
spirem, i. e. there are thin places in the nuclear thread in which little 
or no chromatin is present (PL XVII, Figs. 1-3). There is no definitely 
recognizable differentiation in the cytoplasm at first. This appears to be 
a uniformly granular network or alveolar structure. The first indication 
of the development of the spermatozoid, as has been correctly observed 
by Belajeff, is the withdrawal of the nucleus towards one side of the cell, 
and a slight contraction of the entire protoplast. That part of the lateral 
wall towards which the nucleus moves will be next to the convex side 
of the developing sperm. This is spoken of as the dorsal side by Belajeff. 
The first indication of a cytoplasmic differentiation observed by me appears 
in the form of a very delicate thread or band extending partly around the 
cell and embracing the nucleus in its arc (Fig. 1). This thread seems 
to be merely a differentiation of the plasma-membrane. The end of this 
thread, which will become the anterior end of the sperm, is thinner than 
the opposite or posterior end. In Fig. 1 the anterior end is below the 
nucleus, and the posterior above. The row of sharply defined granules 
included in the concave side of the posterior part of the spermatozoid, 
and which can be so readily observed in later stages, has just begun to 
appear. This line of granules marks the line of separation between the 
posterior end of the sperm and the general cytoplasmic body of the cell. 
I do not agree with Belajeff that these ends are separate, but that they 
are the ends of a continuous thread, the blepharoplast, which in the 
majority of cases is obscured where it lies next to the nucleus. That 
this interpretation is correct is seen in later stages, where the cell has 
been shrunken by the reagents (Fig. 5). I was not able to observe any 
cytoplasmic knob or protuberance (Hocker) from which the cilia arise 
as described by Belajeff, nor does the band or thread extend around 
the middle of the cell in a groove. In this respect my observations 
agree with those of Strasburger (’ 92 ), who did not observe any groove. 
About the same developmental stage shown in Fig. 1, or perhaps a little 
later, is represented in Fig. 2, as seen from the side or in longitudinal 
section. The band is seen to lie along one end of the cell. In this figure 
it will be further noticed that, on the side near the band, the cytoplasm 
has become denser, while on the opposite side there are a very few 
granules in the very delicate cytoplasmic network. This portion of the 
cell, which is comparatively free from granules, might easily be taken 
