402 NERVOUS SYSTEM. 
then divides two or three centimeters distad of the head of the 
fibula into two main branches, N. peroneus superficialis (¢) 
and N. peroneus profundus (/). 
(1) N. peroneus superficialis (g).—The superficial peroneal 
nerve passes distad between the peroneus longus and peroneus 
tertius. Near the ankle it becomes superficial, passing along 
the concavity of the ankle across the transverse ligament which 
binds down the tendons of the extensor longus (23) and tibialis 
anterior (22), and thus reaches the dorsal side of the foot. Two 
or three minute twigs are given off to the ankle, then the nerve 
divides into four divisions. These pass distad to the toes, sub- 
dividing so as to send a nerve to each side of each toe. 
(2) N. peroneus profundus (/).—The deep peroneal nerve 
passes between the tibialis anterior and extensor longus digi- 
torum muscles, gives branches to these muscles, and passes 
distad with the tibialis anterior artery, lying on the inner sur- 
face of the tibialis anterior muscle. It passes onto the dorsum 
of the foot, lying on the inner surface of the tendon of the 
muscle. On the tarsus it divides into two branches. The 
lateral branch passes into the extensor brevis digitorum, 
while the medial one extends in the dorsal groove between 
metatarsals four and five to the toes; here it divides into two 
nerves which supply the contiguous sides of digits four and 
five. 
b. N. tibialis (c¢).—The tibial nerve passes distad parallel 
with the peroneal nerve, but mediad of it. It passes between 
the lateral and medial heads of the gastrocnemius, giving 
off muscular branches to these, and to the plantaris and 
soleus. It then passes between the plantaris and the medial 
head of the gastrocnemius, and reaches the space between the 
plantaris and flexor longus hallucis, where it passes distad. It 
gives off, inthe region just described, muscular branches to the 
flexor longus digitorum, flexor longus hallucis, and tibialis 
posterior. Below the middle of the lower leg the nerve 
becomes superficial (Fig. 127, 2, page 310), lying on the ven- 
tral surface of the flexor longus hallucis. It passes in the 
depression between the heel and the medial malleolus onto the 
Plantar surface of the tarsus, sends a small branch to the 
