Oo 
o/2) 
[oP 
_ The Nerves and Muscles of the Leg 
found relatively more frequently in males (9.3%) than in females 
(5.4%) and in white (10.8%) than in negro subjects (6.4%). In most 
instances an anastomotic branch could be traced to the cutaneous branch 
arising from the obturator nerve. The following table shows the fre- 
quency with which accessory obturator nerves of various types of origin 
were associated with various types of lumbo-sacral plexuses. 
TABLE XI. 
| 
Type of Plexus from which the 
We Gut: Moninakoarisos: Origin of Accessory Obturator. 
| “Most Distal | From(XXI) | From (XXII) | prom XXIV 
Type.| Furcal Nerve. Spinal Nerve | (XXII) XXIII) XXIII XXIV) z 
to Limb. Sp. Nerves. Sp. Nerves. Sp. Nerve. 
Biy,|) <XOXSINW. XXVIT. 1 | 1 
XXIV 
C | chiefly to sac- XOX VITM 5 2 | 1 
ral plexus. 
XXIV | | 
D | ecniefly to lum- DONA OIE 2 5 2 
bar plexus. 
F EXOXGD Vi XXIX. 1 
—|— | 
G (XXIV) sss | 
XXV. XXIX. 1 | 
V. CUTANEOUS NERVES OF THE SCIATIC GROUP 
The cutaneous nerves originally extending toward the posterior and 
distal margins of the embryonic limb are greater in number and have a 
more extensive distribution than those of the anterior border. They 
consist of the posterior cutaneous nerve of the thigh, n. cutaneus femoris 
posterior (small sciatic), with its cluneal, perineal, hamstring and termi- 
nal branches, and the cutaneous rami which arise from the peroneal and 
tibial nerves. We may consider first the early embryonic development of 
these nerves and then the variations found in the adult. 
a. Embryonic Development. 
1. N. Cutaneus Femoris Posterior. 
In Embryo CXLIV, length 14 mm., Plate IV, Figs. 1 and 2, two 
nerves may be seen extending out toward the posterior margin of the 
base of the hmb. One of these nerves represents the posterior cutaneous 
nerve, the other either the perineal ramus (inferior pudendal) of that 
nerve or the perforating cutaneous nerve. The gluteus maximus muscle 
