THE NERVES. 415 



plexus, arises, especially, from the second, third, and fourth lum- 

 bar nerves, passes rather obliquely downwards, outwards and for- 

 wards, behind m. psoas, then before m. iliacus, behind lig. Pou- 

 partii upon the anterior surface of the thigh, where it immediately 

 divides into two principal branches. Situation: in the fossa ili- 

 aca ; in the fossa between psoas and iliacus covered by the fascia 

 iliaca on the external border of the psoas ; behind the lig. Pou- 

 partii ; separated from the art. cruralis by its sheath and the 

 tendon of psoas, below the femoral ring. Branches : to m. psoas 

 and iliacus pectinceus [?] and the following : 



1. N. cutaneus femoris anterior internus comes off at Pou- 

 part's ligament, and descends as far as the outer surface of 

 the knee. It gives branches to m. sartorius and supplies the 

 skin of the outer surface in the centre, and that of the ante- 

 rior and internal in the lower third of the thigh. 



2. N. cutaneus femoris anterior medius arises from the anterior 

 and internal principal trunk, descends in the lower third of 

 the thigh outwards, and terminates above and outside the 

 patella. 



3. N. patellaris arises next to the last on the outside, below lig. 

 Poupartii, supplies the skin on the internal and anterior part 

 of the lower extremity of the thigh, and turns over the pa- 

 tella to the anterior part of the superior extremity of the leg. 



By anastomoses between the external cutaneous nerves, 

 loops and superficial plexuses arise upon the inferior 

 part of the patella. 



4. Rami musculares for : tensor fascice (sometimes [?]), for 

 vastus ezternus (from three to four), internus (one), m. sar- 

 torius, several, superficial and deep, which, perforating the 

 muscle, pass to the skin on the inner side of the knee ; for 

 rectus femoris and cruralis. 



5. Nero, saphenus magnus,\\\e principal branch of n. cruralis, 

 passes as far as the middle of the thigh on the outer side of 

 art. cruralis above the passage of the last through m. adductor 

 magnus, and divides into an internal and a larger external 

 branch. 



a. Ram. internus passes over art. cruralis, behind m. sar- 

 torius, then perforates it and passes on the internal sur- 

 face of the knee-joint to the anterior of the shin-bone to 

 ramify in a radiating form in the skin over its upper 

 third. A branch passes backwards to the middle of the 

 thigh. 



b. Ramus ezternus is larger, passes over the art. cruralis 



