134 ANTHROPOLOGY. 
to which it sends off various muscular and cutaneous branches. The ante- 
rior or radial nerve supplies the supinator longus muscle, along which it 
descends, and passing behind its tendon about the middle of the forearm, 
becomes cutaneous; continuing in its decent, it divides into two consider- 
able branches on the back of the head. The deep branch, or the posterior 
interosseal nerve, is larger than the radical; winding around the upper part 
of the radius, it descends along the back part of the forearm, and divides 
into several branches, superficial and deep, which supply the two layers of 
extensor muscles. 
Pl. 137, fig. 16 (see jig. 15, for the four superior cervical nerves), deep 
cervical nerves; brachial plexus: *, facial nerve; *, vagus; *, internal carotid 
artery ; *, accessory nerve; °*, its connexion with the cervical nerves; °, hypo- — 
glossus; *, anterior branch of the first cervical nerve, uniting with the hypo- 
glossus and vagus; °, connecting branches of the second and third cervical 
nerves with the hypoglossus; *, phrenic nerve; *” , deep branches of the 
cervical plexus; “, brachial plexus; “, the nerve for the subclavian muscle 
giving off a branch to the phrenic nerve; “, anterior thoracic nerve; “, pos- 
terior do.; ** ** '", branches of the subscapular nerve, to the subscapularis, 
the latissimus dorsi, and teres muscles; “, axillary artery, embraced by the 
brachial plexus; “, brachial branches of the brachial plexus. 
Pi. 188, fig. 1, cutaneous nerves of the arm, on the dorsal side: *, cutane- 
ous branches from the axillary nerve; * *, from the radial nerve; * *, branches 
of the internal cutaneous; * *, branches of the external cutaneous; °, union 
of one of these branches with the radial nerve; °, dorsal branch of the ulnar 
nerve with its digital branches; ', dorsal branch of the radial nerve and its 
digital branches; *, connecting branches between the radial and ulnar 
nerves; °, bifurcation of a digital nerve. 71g. 5, *, trapezius muscle; ?, rhom- 
boideus do.; *, accessory nerve; * *, deep posterior branches from the cervical 
and brachial plexus; ', supra-scapula nerve; ‘°, axillary nerve or circumflex 
nerve of the arm. 
The share of the brachial plexus possessed by each nerve of the superior 
extremities in the brachial plexus may be expressed as follows, the figures 
referring to the 5th, 6th, 7th, and 8th cervical nerves, and to the 1st dorsal 
nerves, which together constitute this plexus. 
The supra-scapular nerve, 5, 6, or 5, 6, 7. 
The subscapular nerve, 5, 6, 7, 8, or 5, 6, 7. 
The anterior thoracic, 5, 6; the posterior often 8, 1. 
The great internal cutaneous nerve of the arm, 8, 1, or 7, 8, 1, or 1. 
The musculo-cutaneous nerve, 5, 6, 7, or 5, 6, or 5, 7. 
The axilliary nerve, 5, 6, 7, or 5, 6, or 5, 6, 7, 8, 1. 
The radial nerve,"5;:6,7, 8, or 5, 6, 7, 8, 1) or 6; 7, 8, o0r6; 7, Sahar GS, 
6 TPort, 8: 
The ulnar nerve, 5, 6, 7, 8, 1 or 5, 6, 7, 8, or 6, 7, 8, 1, or 6, 7, 8, or 7, 8, 
I; oF 881) 
The median nerve, 5, 6, 7, 8, 1, or 5, 6, 7, 8, or 5, 7, 8, 1, or 6, 7, 8, 1, or 
5 Spiel, of ok 
The posterior thoracic, 5, 6, 7, 1. 
840 
