Ovaries on Day 0 of the Estrous Cycle.

Ovaries on Day 0 of the Estrous Cycle.
Day 0 = estrus. The active left ovary shows a (functionally) regressed CL and 2 follicles. Legend: 1 = follicle, 2 = corpus luteum, 5 = ovarian stroma.

Pieterse MC (1999)