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3 and 4 were found. The two varieties were about evenly divided. Of 
the stalked variety there seemed to be few follicles with more than two 
or three pronounced cavities. 
The normal follicle of Cymatogaster presents no novelties. As the 
egg ripens the granulosa cells become very high and narrow columnar, 
but remain ip a single series. 
As before stated, occasionally there are found, in this species, follicles 
in which the granulosa is made up of a great many layers. of flattened 
and polyhedral cells. Such a one is represented in Fig. 6. Those cells 
immediately surrounding the ovum and those next the follicular wall are 
noticed to be somewhat flattened, while those intermediate are more 
rounded and polyhedral. The ovaries, which contain such follicles, are 
-comparatively few, but where one such follicle is found, usually two or 
three more may be found. No indication of follicular cavities has been 
observed, but the similarity of such follicles to certain stages of the mam- 
malian follicle is at once evident. Compare Fig. 6 with Fig. 2. 
If, now, follicular cavities should be formed and filled by an accumu- 
lation of follicular fluid we should have conditions similar to those of 
Figs. 2 and 3. 
In oviparous fishes, in batrachians, in birds, in monotremes and in the 
early stages of mammals, we find the follicles one layered. In the adult 
stages of marsupials and higher mammals, where the eggs are very small, 
we find the many layered condition. 
The occasional multilayered follicle in the ovary of Cymatogaster, 
whose egg is but .2-.8 mm. in diameter, seems to bridge the condition found 
in normally large yolked eggs and the minute eggs of the higher mammals. 
The material examined was collected by Dr. C, H. Eigenmann on the . 
coast of California. 
EXPLANATION OF FIGURES. 
Vig. 1-3. Three stages in the development of the follicle of the cat. 
Vig. 4. Follicle of the rabbit. 
Fig. 5. Normal mature follicle of Cymatogaster. 
Fig. 6. Abnormal follicle of Cymatogaster showing the small egg in 
the center of a many layered granulosa. 
Iig. 7. Part of the granulosa layer of Fig. 6, enlarged. 
