OVUM IN THE CAPE AND NEW ZEALAND PERIPATUS. 15 
certain that these must have migrated from the latter, a process 
which would be simple in the absence of any separation between 
the ovum and the follicle. A few yolk-spheres were present in 
the tissue of the follicle itself. There was no trace of any 
germinal vesicle or germinal spot. The shell was thin. This 
ovum measured 3 mm. in its greatest diameter ; as I neglected 
to measure these eggs before cutting, I am not able to state 
their length. 
At the next stage on which I have observations, and which 
was found in an ovum from the same ovary as the last, there 
is a considerable increase in size, the ovum measuring *5 mm. 
in diameter. This increase seems to be due principally to a 
much greater abundance of yolk-spheres in it, the protoplasm 
being distributed among them as a very loose or sparse reti- 
culum. The most remarkabie fact about the ova of this stage 
is that the stalks by which they are connected with the ovary 
are hollow. One of these eggs is shown, in section, in fig. 32. 
As is there shown, the wall of the follicular stalk thins out 
where it reaches the ovum, and passes imperceptibly into its 
wall. In the hollow of the stalk there are a large number of 
yolk-spheres and a few nuclei, resembling those of the walls 
of the stalk, which appear to be passing down it into the ovum 
from the ovary, which contains in its cavity a large amount of 
yolk, as is shown in fig. 26, which represents a transverse 
section through this ovary. There are a few nuclei of the walls 
of the stalk, which appear to be about to be detached and 
pass into its cavity. There are none of these small nuclei in 
the deeper part of the ovum, from which I infer that they, 
together with those which had migrated from the follicle in the 
previous stage, became converted into yolk. 
In the next stage, a transverse section through an ovum of 
which is represented in fig. 30, there has been a slight increase 
in size, the diameter being 56 mm. This ovum is completely 
filled with yolk, and no protoplasm is present, except in the 
form of a large, nearly round nucleus, which lies just beneath 
the point of attachment. This nucleus stains deeply and uni- 
formly, with the exception of a few more deeply staining 
