PHYSIOLOGY, AND PATHOLOGY OF THE CHIMPANZEE. 387 



branch of the axillary artery in Man. No branches come from 

 the second and third parts of the subclavian. 



The Acoillary Artery has the same course and relations as in 

 Man. It has the additional deep i-elation to the axillary 

 prolongation of the air sac. It gives off the following 

 branches : — - 



1. Thoracico-acromial axis (T.A.A), which is not so complex 

 as in Man. It supplies the pectoralis major, deltoid, and the fat 

 and lymph glands in the axilla. 



2. A muscidar artery supplying twigs to the subscapularis. 



3. The subscapular artery (S.U.A) gives off branches which 

 arise separately in Man. These ai'e : — a, A branch which runs 

 to the inferior angle of the scapula between the teres major and 

 latissimus dorsi, and supplies the latter; h. A humeral trunk, 

 which divides into the anterior and posterior circumflex arteries. 

 These form an anastomosis round the neck of the humerus, and 

 the posterior circumflex gives a descending branch, which anasto- 

 moses with the profunda branch of the brachial artery ; c. artery 

 to the teres major ; the main stem then runs down the axillary 

 border of the subscapularis, and ends in the infraspinatus at 

 the inferior angle of the scapula. Its circumflex branch supplies 

 the infraspinatus, passes through the great scapular notch, and 

 ends in the supraspinatus. There is no marked anastomosis 

 round the scapula as there is in Man. 



The Brachial Artery (text-fig. 39 B) differs from that in Man. 

 It becomes the ulnar artery three inches below the internal 

 humeral condyle. It lies superficial to the median nerve through- 

 out, as in the Cercopithecidse. Its branches are : — 



1. Superior Profunda (S.P.A) divides into two branches, 

 which embrace the musculo-spiral nerve. One branch follows 

 the nerve, anastomoses with the descending branch of the pos- 

 terior circumflex arteiy, supplies the triceps and ends in it. An 

 ascending twig ends in the latissimus dorsi. The other branch 

 curves mesially round the humerus, and supplies the deltoid and 

 triceps. 



2. A large artery (M.A) to the biceps, braehialis anticus, and 

 triceps. 



3. Three muscular arteries to the braehialis anticus (Br.A). 



4. Two muscular arteries to the biceps (Bi). 



5. Articular to the elbow joint (Art. A). 



6. Radial artery (R.A). 



7. A muscular artery to the triceps and muscles arising from 

 the external supracondylar ridge and external epicondyle 

 (Arl.A). 



8. Articular artery to the elbow joint. 



9. Muscular arteries to the deep flexors and extensors (D.F). 



10. Radial recurrent artery (R.R.A). 



11. Muscular to the superficial flexor muscles (S.F.M). 

 \2. Anterior interosseous artery {K.Il. A): 



