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IN MAN AND OTHER MAMMATLIA. 359 
primordial ovum, the nucleus, which at first appears ill-defined and semi-solid, 
and is surrounded by a comparatively small quantity of protoplasm, now shows 
a remarkably clear definition, and at last appears as a spherical vesicular body 
with a fine double-contoured wall, and within it one or two nucleoli are usually 
seen. The nucleus of each germ epithelial corpuscle becomes the germinal vesicle 
of the primordial ovum, and the nucleolus corresponds to the germinal spot. 
The ordinary germ epithelial corpuscles measure in their longest diameter 
about +~45pth of an inch, and in their shortest about 5,5 9th of an inch, but 
both these measurements vary considerably. 
On referring to WALDEYER’S work “ Eierstock und Ei,” plate ii. figs. 9, 11, 13, 
I find that he represents the germ epithelial corpuscles as little bodies in which 
the nuclei are comparatively small, while the protoplasm round these is in all 
cases very extensive. This is not in accordance with my observations. An 
examination of the ovaries of numerous foetal and newly-born animals clearly 
shows that in each ordinary germ epithelial corpuscle the nucleus constitutes by 
far the greater part of the corpuscle, the protoplasm around it being in the form 
of a fine film. In the primordial ova, however, the enlarged nucleus has around 
it a correspondingly large quantity of protoplasm, and then these bodies present 
the appearance as described by WALDEYER. 
(b.) The Relation of the Germ Epithelium to the Peritoneal Epithelium.—tin a 
section of the ovary of a 74 months’ foetus, the stalk or peduncle (fig. 8, 5) is 
directly continued into the ovary to form the stroma, which we described as 
arranged in the form of a mesh-work. If we now direct our attention to the 
epithelium covering this stalk (fig. 9,7), we find it is directly continuous with 
the peritoneal epithelium, and on the other hand passes without a break into the 
epithelium which covers the ovary, but a gradual change in its character takes 
place as it slides into and becomes continuous with the latter. 
In the peritoneal epithelium (fig. 9,7), as seen in profile, the nuclei of 
the cells are oval and flattened from above downwards, and are placed at a 
considerable distance from each other, and the protoplasm around them is 
extensive. Tracing this epithelium towards the ovary, as we approach the 
latter, we observe the nuclei of the epithelial cells to become round and 
columnar, and gradually to lie closer together until at last they are almost in 
contact. They then crowd together, and in the form of a thick layer pass on to 
the surface of the ovary as the corpuscles of the germ epithelium (/). As the 
corpuscles of the peritoneal epithelium gradually slide into those of the germ 
epithelium, we find the protoplasm which invests the nuclei of the former 
gradually becomes less and less in quantity, and the nuclei themselves become 
gradually larger and more columnar, until at last the nuclei pass on to the sur- 
face of the ovary as distinct columnar bodies,each having round it a fine invest- 
ment of protoplasm. In thus tracing the peritoneal epithelial corpuscles into 
