DE. J. MUEIE ON THE .iKATOMT OF THE SEA-LION. 541 



The ulnar artery. — From the main artery below the elbow-joint a short flange pro- 

 ceeds ulnarwise, and at a quarter of an inch distance splits into three. One slants across 

 the ulnar head of the flexor sublimis and goes down the arm as the ulnar artery to the 

 wrist, there splitting into three small digital vessels. These three vessels are distributed 

 to the fifth and fourth digits. The outer one, given ofi' highest, runs along the ulnar 

 side of the fifth digit ; the next goes a short way single and then divaricates, one branchlet 

 supplying the radial side of the fifth digit, the other the ulnar side of tiie fourth digit. 



From the short trunk above spoken of the anterior ulnar recurrent diverges upwards 

 toward the joint. The posterior ulnar recurrent is derived immediately below the 

 above, and at an angle from the ulnar. It enters the substance of the flexor carpi 

 ulnaris and the palmaris longus muscle. 



Eadial artery. — This, the chief continuation of the brachial into the forearm, passes 

 downwards over the biceps and brachialis anticus muscles in front of the inner condyle, 

 and afterwards beneath the pronator radii teres and the flexor carpi radialis. In the 

 forearm it is situated nearly in the middle of the broad radius, superficial to and partly 

 on the ulnar side of the radial head of the conjoined flexor profundus and poUicis. The 

 tendon of the palmaris longus secundus obliquely crosses the artery above the wrist- 

 joint. Dipping beneath the superficial palmar fascise, it then, at the proximal end of the 

 metacarpals, splits into three divisions which form the main portion of the palmar arch. 

 The largest poUicial branch crosses the radial side of the second metacarpal and sub- 

 divides into two twigs which proceed respectively to the ulnar side of the poUex and 

 radial side of the second digit. The second middle branch similarly subdivides into a 

 couple of twigs, which run along the ulnar side of the second and radial side of the third 

 digit. The third branch comes off" the highest of the three, and, subdividing at the 

 proximal end of the proximal phalanx, bifurcates, one twig going to the ulnar side of 

 the third, and the other to the radial side of the fourth digit. This palmar arch is 

 superficial to the nerves. 



Below the elbow and in the upper part of the forearm the radial sends off a recurrent 

 branch, chiefly distributed to the muscles on the humerus and radial side of the joint. 

 Other muscular branches are distributed in the forearm. 



Interosseous vessels. — Immediately below the derivation of the ulnar the common 

 interosseous artery strikes off and is about half an inch long, it then splits into two 

 branches. One of these, the posterior interosseous artery, dips between the radial 

 and ulnar heads of the deep flexors above the oblique ligament. It is distributed to 

 the pronator teres, extensor ossis metacarpi pollicis, &c. The second branch forms 

 the anterior interosseous artery, from which, an inch below the commencement 

 of the posterior interosseous artery, a muscular offshoot of moderate size diverges 

 radially and goes to the long muscles of the radial side. A small branch, repre- 

 senting the recurrent, goes upwards to the elbow-joint beneath the external lateral 

 ligament. 



VOL VIII. — r.vRT IX. June, 187i. . 4r 



