1894.] ANATOMY OP ATHEEUEA ATEICANA, 691 



teudon of the psoas parvus ; it supplies the skin of the outer side 

 of the thigh. 



The anterior crural nerve rises from the 3rd and 4th L. and 

 emerges from the front of the psoas beneath Pouparf s ligament ; 

 it then gives off a large cutaneous branch, which soon divides into 

 anterior and posterior branches to supply the inner side of the leg ; 

 the anterior branch supplies the skin of the front of the inner side 

 of the thigh and leg as far as the dorsum of the foot. In company 

 with this cutaneous branch, from the superficial surface of the 

 anterior crural, a branch is given off to the pectineus, which enters 

 it on its deep surface. The rest of the anterior crural supphes 

 the quadriceps, but does not supply the sartorius. 



There is no long saphenous nerve apart from the cutaneous 

 branch already described. 



The obturator nerve rises from the 3rd and 4th L. and emerges 

 from the inner side of the psoas ; it pierces the obturator 

 membrane supplying the obturator externus, after which it divides 

 into branches for the pectineus, adductors, and graciles. 



There is no accessory obturator. The sacral plexus is formed 

 by the 5th L. and the 1st and 2nd S., joined by a branch from the 

 obturator. From the cord formed by the last L. and the branch 

 of the obturator, a nerve is given off to supply the sartorius, 

 tensor vaginae femoris, and gluteus maximus, while close by twigs 

 are given off to the other gluteals and short external rotator 

 muscles. 



The nerve to the hamstrings is nearly as large as the great 

 sciatic ; it is derived from the 5th L. and 1st S. 



The great sciatic comes from the whole of the plexus, but the 

 twig from the 2nd S. is very small. It runs down the back of the 

 thigh as in Man, and gives off a cutaneous branch corresponding 

 to the small sciatic. It divides into external and internal popliteal 

 in the lower third of the thigh. The external popliteal gives off 

 a branch corresponding to the communicans fibuiaris of human 

 anatomy, which pierces the biceps to supply the sldn of the back 

 and outer side of the leg; after this it divides into musculo- 

 cutaneous, anterior tibial, the nerves to the peronei and nerves to 

 the extensor muscles of the leg. The musculo-cutaneous runs 

 down to the dorsum of the foot. The anterior tibial supplies the 

 extensor brevis digitorum and the skin of the contiguous sides of 

 the 2nd and 3rd and 3rd and 4th toes. The internal plantar nerve 

 gives off the short saphenous nerve to the back of the leg and 

 outer side of the foot, after which it- runs down the leg as the 

 posterior tibial, supplying the superficial and deep muscles of the 

 calf. At the ankle it divides into the external and internal 

 plantars, which, in their distribution, correspond to the ulnar and 

 median nerves of the hand. The external plantar supplies all the 

 muscles of the sole except the flexor brevis digitorum and abductor 

 hallucis, but gives off no cutaneous branch. The internal plantar 

 supplies these two muscles and the skin of aU the toes on their 



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