1 92 Proceedings of the Royal Physical Society. 



abdomen, the sartorius, the pectineus, and the four divisions 

 of quadriceps in the thigh. 



The external cutaneous nerve was formed by two roots, 

 one from the 2nd and one from the 3rd lumbar nerve. It 

 passed out of the abdomen behind Poupart's ligament, and 

 supplied skin on the outer side of the thigh and knee. 



The great sciatic nerve was formed by a small branch 

 from the 4th lumbar, practically the whole of the 5th and 6th 

 lumbar nerves, and a small branch from the 1st sacral. The 

 small descending branch of the 4th lumbar joined with the 5th 

 to form what corresponds to the lumbo-sacral cord in man. 



Before the last two lumbar nerves joined they each gave 

 off a branch from their dorsal aspect. These two branches 

 united and formed the superior gluteal nerve, which passed 

 out of the pelvis through the great sciatic notch above the 

 pyriformis, and supplied the gluteus medius, both divisions 

 of the tensor fasciae femoris, and all the four divisions of the 

 gluteus minimus. 



The great sciatic nerve, or sacral nerve cord, passed out of 

 the pelvis through the great sciatic notch below pyriformis. 

 It proceeded downwards through the gluteal region super- 

 ficial to the gemelli and quadratus, entered the thigh, and 

 ran downwards under cover of biceps between the caudo- 

 femoralis and gluteus maximus. In the middle of the thigh 

 it ended by dividing into two— the internal and external 

 popliteal. All its branches were given off in the gluteal 

 region, and in the following order : — 



1. Two branches to the gluteus maximus, one to the upper 

 and one to the lower division. The lower branch was joined 

 by a twig from the 2nd sacral nerve. These each divided 

 into several branches before entering the muscle. 



2. A branch to the quadratus femoris. This nerve ran 

 downwards under cover of the gemelli and the tendon of 

 obturator internus, and supplied a branch to the capsule of 

 the hip joint, and another to the inferior gemellus, before 

 entering quadratus. 



3. A branch which joined the internal pudic, but left that 

 nerve again to supply the obturator internus on its perineal 

 surface. 



