OVUM IN THE CAPE AND NEW ZEALAND PERIPATUS., 9 
which radiate from the pronucleus towards the centre of the 
egg. 
In all the other ova of P. capensis in which the formation 
of polar bodies was taking place, I was unable to see any pro- 
nucleus, although I believe that that structure must be present 
in them, since it seems certain that fertilization must take 
place in the ovary. In several cases there were special aggre- 
gations of protoplasm, in one of which the male pronucleus 
may have been present, although I was not able to distinguish 
it, and I am inclined to think that for a short time after 
entering the ovum it is invisible, possibly from a lack of 
chromatin. 
In the next stage, when the polar bodies are both formed, 
the male and female pronuclei are both present as very well- 
marked structures. Two sections through an egg of this stage 
are shown in figs. 14a and 145. Fig. 14a passes through the 
second polar body and the female pronucleus ; the former lies 
in a depression on the surface of the ovum and is not com- 
pletely separated from it, being connected with its proto- 
plasmic reticulum; it contains three chromatin granules. 
Just below it lies the female pronucleus, which is now in the 
resting condition, and has begun to assume the lobed structure, 
which was described by Mr. Sedgwick (15) as being so charac- 
teristic of the segmentation nuclei, and is divided by a septum 
into two compartments, in each of which are a few chro- 
matin granules. It is not surrounded by any special dense 
protoplasm, but its wall is continuous with the general loose 
reticulum of the egg. Fig. 14 6, which is several sections 
removed from fig. 14a, passes through the male pronucleus, 
which is now a very prominent feature in the egg. It is 
round in shape, and lies near the centre of the egg, being con- 
nected with the periphery at the side removed from the female 
pronucleus by a denser mass of protoplasm, which in transverse 
section is roughly wedge-shaped. In these two figures only 
the protoplasm in the neighbourhood of the pronuclei is figured. 
Seen under a high power, the male pronucleus is seen not 
to be sharply marked off from the extra-nuclear substance, 
