510 NERVOUS SYSTEM. 



tens,) having the direction mentioned, is placed between the 

 skin and the popliteal vein. It gets between the heads of the 

 gastrocnemius muscle, and perforates the origin of the soleus; 

 going with the posterior tibial artery, between this muscle and 

 the flexor longus digitorum, to the bottom of the leg. It gives 



off the following branches: 



\ 



a. The External Saphenus, (Saphenus Externus, or Com- 

 municans Tibice,) which arises above the knee-joint, and, de- 

 scending between the skin and the gastrocnemius, turns out- 

 wardly, and anastomoses with the cutaneous branch, alluded to, 

 of the peroneal nerve. The common trunk, thus formed, passes 

 behind the external ankle, along the external margin of the 

 foot, and terminates on the outer toes, having given off a great 

 number of cutaneous branches. 



b. Branches to the heads of the gastrocnemius, soleus, plan- 

 taris, and popliteus. 



c. Branches to the flexor longus digitorum, tibialis posticus, 

 and to the flexor longus pollicis pedis. 



d. A branch through the interosseous ligament, above, to the 

 tibialis anticus. 



e. At the inferior part of the leg many cutaneous filaments, 

 one of which gets to the sole of the foot. 



The Posterior Tibial Nerve, having given off these branches, 

 divides, in the hollow of the os calcis, into the Internal and the 

 External Plantar Nerve. 



The Internal Plantar (Plantaris Iniernus) proceeds along- 

 side of the tendon of the flexor longus muscle of the great toe, 

 and the flexor longus digitorum, and gives filaments to the con- 

 tiguous muscles. It then divides in such a way as to furnish 

 the two sides of the first three toes and the internal side of the 

 fourth. 



The External Plantar (Plantaris Externus) proceeds with 

 the artery of the same name to the outer edge of the foot, be- 

 tween the flexor brevis digitorum and the flexor accessorius. 

 It is distributed to the two sides of the little toe, and to the ex- 

 ternal side of the fourth toe. One branch penetrates to the in- 

 terosseous muscles and to the transversalis pedis. A branch 

 of considerable size is also detached, near the heel, to the 

 muscles and integuments connected with the os calcis*- 



