590 SPINAL NERVES. 



sending a filament to the first Lumbrical muscle; the third digital branch supplies 

 the adjacent sides of the second and third toes, and the second Lumbrical muscle ; 

 the fourth supplies the corresponding sides of the third and fourth toes, and 

 receives a communicating branch from the external plantar nerve. It will be 

 observed, that the distribution of these branches is precisely similar to that of 

 the median. Each digital nerve gives off cutaneous and articular filaments; 

 and opposite the last phalanx sends a dorsal branch, which supplies the structures 

 round the nail, the continuation of the nerve being distributed to the ball of 

 the toe. 



The external plantar nerve, the smaller of the two, completes the nervous supply 

 to the structures of the foot, being distributed to the little toe and one half of the 

 fourth, as well as to some of the deep muscles. It passes obliquely forwards 

 with the external plantar artery to the outer side of the foot, lying between the 

 Flexor brevis digitorum and Flexor accessorius ; and, in the interval between the 

 former muscle and Abductor minimi digiti, divides into a superficial and a deep 

 branch. Before its division, it supplies the Flexor accessorius and Abductor 

 minimi digiti. 



The siiperficial branch separates into two digital nerves : one, the smaller of the 

 two, supplies the outer side of the little toe, the Flexor brevis minimi digiti, and 

 the two interosseous muscles of the fourth metatarsal space ; the other, and larger 

 digital branch, supplies the adjoining sides of the fourth and fifth toes, and com- 

 municates with the internal plantar nerve. 



The deep or muscular branch accompanies the external plantar artery into the 

 deep part of the sole of the foot, beneath the tendons of the Flexor muscles and 

 Adductor pollicis, and supplies all the Interossei (except those in the fourth 

 metatarsal space), the two outer Lumbricales, the Adductor pollicis, and the 

 Transversus pedis. 



The EXTERNAL POPLITEAL or PEBONEAL NERVE, about one-half the size of 

 the internal popliteal, descends obliquely along the outer side of the popliteal 

 space, close to the margin of the Biceps muscle, to the fibula ; and, about an inch 

 below the head of this bone, pierces the origin of the Peroueus longus, and 

 divides beneath this muscle into the anterior tibial and musculo-cutaneous nerves. 



The branches of the peroneal nerve, previous to its division, are articular and 

 cutaneous. 



The articular branches, two in number, accompany the superior and inferior 

 ' external articular arteries to the outer side of the knee. The upper one occa- 

 sionally arises from the great sciatic nerve before its bifurcation. A third 

 (recurrent) articular nerve is given off at the point of division of the peroneal 

 nerve ; it ascends with the tibial recurrent artery through the Tibialis antic us 

 muscle to the front of the knee, which it supplies. 



The cutaneous branches, two or three in number, supply the integument along 

 the back part and outer side of the leg, as far as its middle or lower part ; one of 

 these, larger than the rest, the communicans peronei, arises near the head of the 

 fibula, crosses the external head of the Gastrocnemius to the middle of the leg, 

 where it joins with the external saphenous. This nerve occasionally exists as a 

 separate branch, which is continued down as far as the heel. 



The Anterior Tibial Nerve commences at the bifurcation of the peroneal nerve, 

 between the fibula and upper part of the Peroneus longus, passes obliquely for- 

 wards beneath the Extensor longus digitorum to the fore part of the interosseous 

 membrane, and reaches the outer side of the anterior tibial artery above the 

 middle of the leg; it then descends with the artery to the front of the ankle-joint, 

 where it divides into an external and an internal branch. This nerve lies at first 

 on the outer side of the anterior tibial, then in front of it, and again at its outer 

 side at the ankle-joint. 



The branches of the anterior tibial, in its course through the leg, are muscular : 

 these supply the Tibialis anticus, the Extensor longus digitorum, and Extensor 

 proprius pollicis muscles. 



