DEVELOPMENT OF THE CAPE SPECIES OF PERIPATUS. 191 
in a very small area of protoplasm in which the network was 
dense as at the opposite pole. This I take to be the male pro- 
nucleus. 
Finally, this ovum possessed the peculiarity of presenting in 
surface views (Part 1, fig. 3) a number of opaque patches. 
These in section are seen to be due to a number of peripher- 
ally placed areas in which the protoplasmic reticulum was 
dense as it is around the female nucleus. The protoplasmic 
reticulum of these denser areas was arranged in a radiating 
manner around a central point ; it presented no deeply-staining 
masses of chromatin. 
6. Two Ova in which the second polar body was 
being formed.—In both of these the nucleus of the ovum 
had already divided into the definite female pronucleus and the 
nucleus of the second polar body, and in both the latter was 
attached by a wide base to the ovum. In one, however, this 
division has only just occurred, and the female pronucleus was 
in the form of some small deeply-staining masses placed close 
to the surface of the egg; the denser protoplasmic reticulum 
of the animal pole around them not being apparently modified. 
The male pronucleus presented the same features as in the 
last described ovum. 
In the other ovum the female pronucleus (PI. XI, fig. 1) 
was in a very different condition to the above. The chro- 
matin masses had acquired a definite relation to the pro- 
toplasmic reticulum, and the whole structure resembled 
in all its essential features the chambered nucleus of the 
fertilised ovum (see above, p. 188). Its greatest diameter 
s ‘029 mm. At the opposite side of the ovum and not 
quite in the same plane (though for the sake of convenience 
the two structures are combined in one figure), there was a 
large (025 x‘016 mm.) reticulated structure, which I take 
to be the male pronucleus (Pl. XII, fig. 1). This male pro- 
nucleus was much nearer the centre of the egg than those 
previously described, as though it were in the act of moving to 
the female nucleus. The network in this nucleus was of vary- 
ing degrees of fineness, and was more deeply stained in some 
