Primordial sex cells are formed in the yolk sac in the presomite embryo. They migrate from this position to the medial aspect of the mesonephric ridge. The epithelium of the mesonephric ridge then proliferates and forms its own ridge called the genital ridge. Two ducts are now recognised as the Wolffian or mesonephric duct and the paramesonephric duct (Mullerian ) ducts bilaterally. The mesonephric duct is associated with the mesonephros and the developing kidney system. In the female, as soon as the sex cells arrive, the epithelium of the genital ridge form sex cords which becomes cut off from the surface epithelium. They will form the primary follicles and begin meiosis shortly before birth. The paramesonephric duct becomes the main duct in the female reproductive system while the mesonephric or Wolffian duct degenerates. The longitudinal parts of the paramesonephric ducts now fuse to form the duct system of the female such as the uterus, the fallopian tubes and the cervix. Cervix is formed from the caudal part, the uterine tubes from the cranial part and the intermediate part forms the uterus. Vaginal plate epithelium is insinuated between the Mullerian tubercle and the urognital sinus. It divides and forms the vagina which later canalises. The mesonephir duct degenerates but forms some vestiges such as the epoophron and paroophoron. The Gartner's duct formed by the caudal part of the mesonephric dut degenerates but may persist as abberation in the adult system.