Endoscope image of a human ovary and fallopian tube (bottom). The image was taken after a ripe ovarian follicle had released its ovum (egg) into the fimbriae (the feather-like opening) of the fallopian tube. Primordial ovarian follicles are formed between the 4th & 7th month of fetal development and develop into primary follicles at sexual maturity. In each monthly ovarian cyle up to 20 follicles may become activated; only one normally reaches full maturity to release an ovum at ovulation. Here, the identation in the surface of the ovary (top) marks the point at which the ovum was released.