An embryonic structure that helps guide proper descent of gonads into their final positions. It attaches the caudal end of the fetal GONADS to the developing SCROTUM in male and the labium majorum in female. It gives rise to the caudal ligaments of the gonad: the scrotal ligament in male and the uterine round and proper ovarian ligaments in female. It includes morphofunctional equivalent structures in non-mammals.