K. Cut open a corpus luteum on one of the ovaries. Note how much of the corpus luteum is below the surface of the ovary.

L. Now look for a small white or slightly brown spot on the surface of the ovaries that is not a tertiary follicle. This is likely to be a corpus albicans (white body) that is actually a regressing corpus luteum. This can be verified by cutting into the structure with a scapel as shown on the right.