The lumbar nerves, like the dorsal, divide, after leaving the spinal cord, into a superior and inferior branch. The former, passing in an upward direction, ramify through to the muscles of the loins, and ultimately reach the skin, where they terminate. The inferior branches are variously distributed. Those of the first two, after supplying the psoas magnus, pass over the edge of that muscle, and are distributed to the muscles of the flank, the skin, and some fine filaments to the muscles of the thigh. The inferior branch of the third nerve supplies the psoas magnus, psoas parvus, and quadratus lumborum, and its ultimate fibres are expended in the skin of the thigh. The fourth, fifth, and sixth lumbar branches contribute to form the lumbo-sacral plexus. All the inferior branches of these nerves are connected with the great sympathetic.