The genital branch of the genitofemoral nerve (external spermatic nerve) arises from the ventral primary divisions of L1 and L2 spinal nerve roots, passes outward on the Psoas major, and pierces the fascia transversalis, or passes through the deep inguinal ring; it then descends behind the spermatic cord to the scrotum, supplies the Cremaster, dartos muscle and gives a few filaments to the skin of the scrotum.