482 
Notes . 
is very remarkable inasmuch as it is entirely intranuclear, somewhat 
resembling that described by Fairchild for Valonia, or by Harper for 
Peziza. The nuclear wall can be distinguished until quite late in 
karyokinesis, and it is possible that no complete mingling of the 
cytoplasm with the contents of the nucleus takes place here. The 
spindle is extremely clear, and in several preparations, owing to 
a fortunate contraction during manipulation, the ends of the nuclear 
part of the spindle also had broken away from the cytoplasmic poles, 
and were visible as clean conical structures forming the poles of the 
nuclear spindle. The chromosomes were too minute to admit of 
their development being satisfactorily studied, but in all the oogonial 
spindles their number was estimated at ten when seen arrayed on the 
spindle equator. They were only seen in profile, and consequently it 
was difficult to be sure whether there were really ten or twelve, but 
the absolute number is not of importance as all the nuclei were com- 
pared from the same aspect. Remains, more or less preserving the 
original form, of the nucleolus were sometimes visible at this and even 
in a later stage. No division-planes are formed in the oogonium 
until the full complement of nuclei are produced; after this the 
positions which they will ultimately occupy are indicated by the 
heaping up into lines (or rather plates) of the cytoplasmic granules 
above referred to. These seem to be repelled equally from all the 
nuclei, thus effecting a symmetrical division of the entire oogonium. 
After the complete delimitation of the oospheres within the oogonium, 
we observed, as an occasional circumstance, that one of the oospheres 
might contain two, or even three, nuclei, a fact also noticed by 
Oltmanns. When the oospheres are extruded, and come to lie free 
in the water, they grow in size, and are turbid with granules, which 
are very abundant in the cytoplasm. The chromatophores early 
become distinguishable from the other constituents of the cell, and 
the nucleus occupies a central position. It is itself surrounded by 
a dense layer of cytoplasm, which later on becomes very strongly 
marked. About five minutes after the mixing of the sexual cells, the 
antherozoids are found to have slipped into many of the oospheres. 
We failed to observe the act of penetration, but found a number of 
cases in which the antherozoid could be recognised within the oosphere, 
before its final fusion with the nucleus of the latter. It is a roundish, 
densely staining body, and, unlike the majority of animal sperm-cells 
as yet described, it imports into the egg no system of radiations along 
