1886.] On the Minute Anatomy of the Brachial Plexus. 255 



March 25, 1886. 

 Professor STOKES, D.C.L., President, in the Chair. 



The presents received were laid on the table, and thanks ordered 

 for them. 



The following Papers were read : — 



I. " Abstract of Paper upon the Minute Anatomy of the 

 Brachial Plexus." By W. P. Herrixgham, M.B., M.R.C.P., 

 Communicated by W. S. Savory, F.R.S. Received March 8, 

 1886. 



The paper is based npon 55 dissections, 32 foetal and 23 adnlt. 



The posterior thoracic is formed by the 5th, 6th, and usnally the 7th. 

 The 5th supplies the first two digitations, the 6th the next two, the 

 6th and 7th the lower five, or if there is no 7th, the 5th may supply 

 three, and join the 6th for the remainder. 



The suprascapular is given off from the 5th, with or without a 

 minute fibre from the 6th. 



The anterior thoracics are formed usually by the 6th, the 7th, the 

 8th, and the 9th. The 6th and 7th form the external, supplying the 

 upper part of the pectoralis major, the 7th gives the communicating 

 branch which supplies the middle, and the union of this with the 

 internal from the 8th and 9th, supplies the lower part of the muscle. 

 The minor is supplied by the 7th, 8th, and 9th. 



The coraco brachialis is supplied by the 7th. 



The rest of the musculo cutaneous is formed by the 5th and 6th. 

 Both nerves enter the biceps and brachialis anticus. The cutaneous 

 branch is mostly from the 6th, slightly also from the 5th. 



The median is formed by the 6th, 7th, 8th, and 9th. 



The 6th supplies the pronator teres, flexor carpi radialis, superficial 

 thenar muscles, and radial finger, or fingers. 



The 7th supplies the flexor sublimis, occasionally the anterior 

 interosseous, the palmar cutaneous, and the finger next the 6th. 



The 8th supplies the flexor sublimis, the anterior interosseous, and 

 the fingers inside the 7th. 



The 9th supplies the anterior interosseous, and usually ends there. 



The ulnar is formed by the 8th and 9th ; the muscles in the forearm 

 are supplied by both, those in the hand by the 8th. The 9th supplies 

 the cutaneous branches in front, the 8th the dorsal branch. 



