Light microscopy of a foetal ovary. Towards the end of foetal development the ovaries contain many oocytes enclosed by follicle cells together called ovarian follicles. Depending on the species there may be several million follicles in each ovary. The foetal human ovary may have up to 5 million follicles in mid-pregnancy but most of these degenerate leaving on average only several hundred thousand per ovary at the time of birth. This specimen is from a monkey at 20 weeks of gestation. Magnification x40 when printed at 10 cm.