The scientific fact is that the primordial cells of the testes in the male or the ovaries in the female accumulate in the backs of the parents during the embryonic stage, then they come out of the back from the area between the start of the spinal column and the start of the ribs, then the ovaries migrate towards the pelvis in the vicinity of the uterus, and the testes migrate to the scrotum where the temperature is lower, otherwise they will fail to produce sperm and become subject to the risk of developing into cancerous tumors if the journey is not completed