PHYSIOLOGY, AND PATHOLOGY OF THE CHIMPANZEE. 367 



suhscaptolar bursa opens into the joint cavity above the superior 

 gleno-humeral ligament. The cof'aco-humeral ligament blends 

 with the capsule near the insertion of the subscapularis. The 

 coraco-acromial arch is a strong band, and there is also a weak 

 acroniio-hiimeral ligament. The insertions of the supraspinatus 

 and infraspinatus are most intimately blended w^ith the capsule, 

 and cannot be separated from it. The posterior part of the 

 capsule is weak and loose, but the anterior part contains a broad, 

 powerful anterior gleno-humeral ligament. The capsule is 

 attached to the bones as in Man. The superior gleno-humeral 

 ligainent divides into two parts, which are inserted separately 

 into the humerus, and the subscapular bursa communicates with 

 the joint between them. The cotyloid ligament and tendon of 

 the biceps are as in Man. 



The Elbow Joint : — The posterior part of the capsule is attached 

 as in Man ; and a strong band passes from the tip of the ole- 

 cranon up to the outer part of the olecranon fossa, which contains 

 fat. The anterior part of the capsule is relatively strong all over. 

 On the radial side the fibres run downwards and inwards, but 

 those on the ulnar side run downwards and outwards. The fibres 

 of these sides interlace and make the capsule strong. The internal 

 lateral ligament is very strong. It arises from the internal condyle 

 and spreads out to be attached to the whole inner margin of the 

 olecranon, the coronoid and the great sigmoid notch. The thickest 

 parts are fixed to the olecranon and coronoid, but it has no trans- 

 verse part. The external lateral ligament is attached as in Man. 

 It is weaker than the internal ligament, but muscles arise from it. 



The Superior Radio- Ulnar Joiyit : — The capsule of the elbow 

 joint is prolonged down for | inch over the head and neck 

 of the radius. The orbicular fibres are as in Man, but there is 

 no oblique cord. The interosseous ligameiit begins at the lower 

 part of the coronoid process. One set of fibres runs downwards 

 and outwards to be inserted into the radius below the bicipital 

 tuberosity. A second group runs from the insertion of the 

 first to the ulnar interosseous border ; it is by far the stronger 

 group, and lies anteriorly. 



The Synovial Cavity of the Elbow Joint : — This is attached to 

 the margin of the coronoid fossa, but more superiorly than the 

 fossa for the head of the radius. Ttie line of attachment then 

 passes about half-way between the articular surfaces and the 

 condyles. On the posterior surface the capsule is attached round 

 the margin of the olecranon fossa. On the radial side the attach- 

 ment corresponds to a line joining the epicondyles and drawn on 

 the part of the humerus which articulates with the radius. On 

 the ulnar side it is attached to the margin of the olecranon fossa, 

 greater sigmoid notch and coronoid, but it' jumps the gap 

 between the margins of the lesser sigmoid notch, where it gives 

 rise to orbicular fibres. 



The Wrist Joint : — The anterior and posterior aspects of the 

 carpus are covered by bands of fibres running in all directions ; but 



