EXPLANATION OP PLATE lUNll— Continued. 

 ovum are fusiform connective tissue corpuscles {n), similar to the fusiform 

 corpuscles of which the stroma consists. Numerous blood-vessels {k), 

 whose walls consist of connective tiss\ie corpuscles, ramify throughout the 

 whole ovary. 



f iG. 7. — A small egg cluster consisting of large splierical germ epithelial 

 corpuscles with fusiform connective tissue corpuscles («) intermingled. 



Fig. 8. —A small group of spherical germ epithelial corpuscles. 



Fig. 9. — A primordial ovum. It has no zona pellucida. 



Figs. 10, 11. — Pririiordial ova (ni). lu contact with and indenting the 

 yelk substance of each, are fusiform connective tissue corpuscles from the 

 wall of the young Graafian follicle. 



Fig. 12. — The membrana granulosa (r) when first formed seen in section. 

 Outside the membrana is the ovarian stroma {j). From the human ovary 

 at birth. 



Fig. 13, — The corpuscles of the membrana granulosa from the nearly 

 ripe Graafian follicle of the rabbit's ovary. The letter v points to the 

 division of the nuclei of the corpuscles. 



Fig. 14. — Surface view of the membrana granulosa (r) when first formed. 

 From the human ovary at birth. 



PLATE XVIIl. 



Figs. 15, 16, 17, 18, 19, 20, illustrate the development of the membrana 

 granulosa in the ovary of an adult rabbit. 



Fig. 15. — A primordial ovum {ni). Fusiform connective tissue corpuscles 

 («) of the stroma (_;) lie in contact with the yelk substance of the young 

 ovum. 



Fig. 16. — A young ovum farther advanced in development than the last. 

 Some of the fusiform corpuscles («) in contact with the yelk are swollen out. 



Fig. 17. — An ovum still farther advanced in development, completely 

 surrounded by a wreath of corpuscles, which have been derived from tlie 

 fusiform corpuscles of the stroma (_/). This wreath is the membrana 

 granulosa (r) seen in section. 



Fig, 18. — A Graafian follicle from which the ovum has been removed 

 The membrana granulosa (r) is seen in section. 



Fig. 19. — A section through a Graafian follicle and the nearly ripe ovum 

 contained in it. The membrana granulosa (r) consists of several layers of 

 corpuscles. The zona pellucida (s) is well developed, and the yelk substance 

 {t) at its peripheral part contains numerous bright granules and particles. 



Fig. 20. — A section through the membrana granulosa and waJJ of a ripe 

 Graafian follicle just before bursting. The membrana granulosa (r) consists 

 of several layers of corpuscles. Each corpuscle is a large nucleus sur- 

 rounded by protoplasm («). In the wall of the follicle outside the mem- 

 brana granulosa the fusiform corpuscles of the stroma {j) are very large. 



Fig. 21. — A. section through the egg zone of an old cat's ovary. The 

 stroma {j) consists almost entirely of fusiform corpuscles. Around the 

 young eggs («) the fusiform corpuscles (n) of the stroma may be traced in 

 their development into the corpuscles of the membrana granulosa. 



Fig. 22. — The epithelium {h^ from the surface of the same cat's ovary. 



Fig. 23. — The epithelium (h^ from the surface of the ovary of a child 

 six years of age. 



Fig, 24. — The same epithelium more highly magnified showing the 

 ** grooved " appearance of the corpuscles. 



Fig. 25. — Germ epithelial corpuscles {h) seen in profile. From the ovary 

 of a seven and a half months' human foetus. 



Fig. 26. — A primordial ovum {m) surrounded with fusiform corpuscles («), 

 From the stroma of the same ovary. 



Fig. 27.— An ovum {t) from the deeper parts of the same ovary, showing 

 the appearance of the membrana granulosa (r) when first formed round the 

 ovum. 



