18 
Psyche 
March 
and close together. During telophase the mitotic figure is 
no longer fusiform, but is a spheroid with long axis about 
14 microns long and short axis about 10 microns long. In 
presumably slightly older eggs a very distinct equatorial 
constriction is evident. The two groups of chromosomes 
separate to a distance of almost 30 microns. In favorably 
sectioned eggs most of the eighteen dyads in each group 
can be distinguished (Fig. 4). Many of the chromosomes 
are very short and V-shaped, so that the dyads look super- 
ficially like tetrads. 
The first polar body is not extruded from the egg and 
does not divide. Its chromosomes never become surrounded 
by a nuclear membrane as do those of the secondary oocyte. 
The dyads gradually change into an irregular mass, which 
remains close to the surface of the egg and disappears 
relatively quickly. No certain trace of the first polar body 
was found later than the anaphase of the second maturation 
division. 
The egg nucleus was never found in a resting stage be- 
tween the maturation divisions. The spheroidal prophase 
nucleus, with its still distinguishable dyads, is believed to 
increase in size, since a series has been found with long axis 
varying from 8 to 15 microns in length. The second matura- 
tion division resembles the first in size and orientation, but 
its chromosomes are slightly more easily distinguishable 
(Fig. 3). The second polar body degenerates as does the 
first and has not been seen with certainty later than the 
four-celled cleavage stage. The chromosomes of the female 
pronucleus enter a resting stage with distinct nuclear mem- 
brane. The nucleus is a spheroid with long and short dia- 
meters of 9 microns and 5 microns respectively. It shows 
hardly any variation from egg to egg. 
In the majority of freshly laid eggs, cytoplasm is seen 
starting to accumulate around one of the sperm heads (Fig. 
1). This sperm and its sperm plasm are typically found on 
the longitudinal axis of the egg, about one-third of the way 
from the posterior pole to the anterior pole. The distance 
from the maturation spindle is roughly 400 microns. If 
several sperms are present in the egg, cytoplasm may or 
may not accumulate around more than one. In cases where 
