[Meiotic prophase in germinal cells of rat ovarian primordium cultivated in vitro in anhormonal medium].

Gonads of female Rat fetuses were cultured in vitro in an anhormonal medium with the whole or parts of the mesonephros, at an age of 12, 13 or 14 days, i.e. 2 to 4 days before the onset of meiosis. Under these conditions the meiotic prophase takes place and proceeds to the dictyate phase, obeying a somewhat delayed chronology in comparison with controls in vivo.