“Upon the egg-bearer” (Greek) refers to a cluster of blind-ending tubules near the ovary of the adult female that are vestiges (remnants) of a male reproductive system, at least, potentially male. Fetuses of both sexes start out with all the basic structures to equip them to develop either a female or male reproductive system including two sets of sex ducts. Potentially female ducts may become a uterus with uterine tubes and potentially male ducts may become an epididymis and vas deferens. Through complex hormonal controls one set of ducts survives and develops appropriate to the sex and the alternate set deteriorates into a few remnants of what might have been. Such a complex apparatus also sets the stage for potential abnormalities in sexual development. The epoophoron is a vestige of an epididymis, entirely nonfunctional in the female, that would have become a structure in a male that is responsible for temporary storage of sperm while they undergo final maturation.