Ovaries on Day 15 of the Estrous Cycle.
The left ovary shows a fully developed corpus luteum with a smaller ovulation papilla than the one in the previous image, perhaps the result of the distension due to the fluid filled cavity which causes the CL to feel rounder. The right ovary shows a large dominant follicle. Legend: 1 = follicle, 3 = corpus luteum with a cavity (lacuna), 5 = stroma.
Pieterse MC (1999)