Section of the ovary. 1. Outer covering.
1’. Attached border.
2. Central stroma.
3. Peripheral stroma.
4. Blood vessels.
5. Vesicular follicles in their earliest stage.
6, 7, 8. More advanced follicles.
9. An almost mature follicle.
9’. Follicle from which the ovum has escaped.
10. Corpus luteum.
Section of the fold in the mesonephros of a chick embryo of the fourth day. (Stroma of ovary labeled at center left.)