UPPER NINE SPINAL NERVES. 497 



position for two or three inches: it goes down the front of the 

 fore arm on its ulnar side, but inclines continually to the back 

 of the fore arm. In this course, it detaches small ramifications 

 to the integuments about the internal condyle, and about the 

 heads of the flexor muscles; it also detaches continually, from 

 its sides, small filaments to the integuments of the ulnar side of 

 the fore arm both anteriorly and posteriorly, some of which 

 reach to the hand. The other, being the anterior, or the ex- 

 ternal branch of the internal cutaneous, which is nearer the 

 radius, passes beneath the median basilic vein, about six lines 

 from the basilic; but, just before it does so, it detaches a very su- 

 perficial cutaneous filament, which crosses in front of the me- 

 dian basilic vein about its middle, and is lost a little below the 

 bend of the arm. The anterior or outer branch of the internal 

 cutaneous having got from beneath the median basilic vein, 

 goes superficially as far as the middle of the fore arm without 

 sending off any filaments of note; it is then divided successive- 

 ly into several, which diverge to supply the skin down to the 

 wrist. 



6. The Nervus Musculo-Cutaneus, or Cutaneus Externus, is 

 somewhat larger than the preceding, and arises from about the 

 middle of the brachial plexus. It descends a short distance, 

 and then perforates obliquely the upper part of the coraco- 

 brachialis muscle. Having passed through this muscle, it con- 

 tinues its course obliquely, between the brachialis inlernus and 

 the biceps flexor, and, finally, makes its appearance superficial- 

 ly on the outer side of the tendon of the latter. In this course, 

 it distributes filaments to the several muscles with which it is 

 connected. 



It afterwards passes the elbow joint under the median cepha- 

 lic vein near its middle, and descends between the skin and 

 the fascia of the fore arm, near the outer margin of the me- 

 dian vein, to the hand: in this course, it is parallel with and 

 on the front of the supinator radii longus. It distributes many 

 filaments to the corresponding integuments on the radial side of 

 the fore arm, and, having at length got near the lower end of 

 the radius, it divides into two orders of fibres, one of which 

 is distributed to the integuments on the dorsal, and the other 



43* 



