14, LILIAN SHELDON. 
and seem to arise in the protoplasm itself. A transverse 
section of an ovum at this stage is shown in fig. 27. As will 
be there seen, the egg is now surrounded by a thin shell. 
The nucleus now loses its evenly spherical form and becomes 
crinkled in outline. This appears to be due to the passage out 
from it of portions of its substance which pass into the extra- 
nuclear tissue in the form of round bodies of various sizes. 
These bodies, like the portion of the nucleus from which they 
are formed, are perfectly homogeneous, and stain with picro- 
carmine a deep yellowish red. This process is shown in 
fig. 28. The small yolk-globules are still present (coloured 
yellow). The shell has increased in thickness. 
This process continues until all the wall of the nucleus is 
dispersed, the central clear part appears to blend with the egg- 
protoplasm, and the nucleolus remains behind lying in the 
protoplasm. This condition is shown in fig. 29. The round 
spheres derived from the nucleus remain unchanged. I believe 
that these round spheres form part of the yolk of the 
ovum, which question I shall further discuss later on in this 
paper. 
All the above stages were very common and occurred to a 
greater or less extent in all the ovaries which I cut of April, 
July, and December, but the older stages, which I shall now 
describe, were only found in the ovary in December, and not in 
either April or July, a fact which supports the statement which 
I made in a previous paper (16) that the ova probably pass into 
the oviduct in December. 
Fig. 31 represents a transverse section through an ovum in 
which a small amount of yolk is present; this is coloured yellow 
in the diagram. A very obvious thing in this ovum is the 
entire absence of any definite boundary line between the follicle 
and the ovum itself, in fact, they pass into one another imper- 
ceptibly. There is a small amount of yolk present in the form 
of scattered spheres throughout the protoplasm of the ovum, 
which latter has a reticular and vacuolate character. There 
are also in the protoplasm small round or oval nuclei which in 
every respect resemble those of the follicle, and it seems almost 
