30 THE ARTISTIC ANATO^LY OF ANIMALS 



sities are on a higher level than the articular head of the 

 bone. Between the two tuberosities is the bicipital groove. 

 In man, the superior extremity of the humerus, although 

 covered by the deltoid, reveals its presence by elevating 

 the corresponding portion of the latter. In quadrupeds, the 

 anterior part of this extremity, although similarly covered by 

 muscular bundles, produces a prominence under the skin. 

 This prominence is situated at the summit of the angle 

 formed by the opposing directions of the scapula and the 

 bone of the arm, and constitutes what is known by 

 the name of the point of the shoulder, or of the point of 

 the arm. 



The inferior extremity, transversely enlarged, presents an 

 undulating articular surface, which reminds us of the trochlea 

 and the condyle of the human humerus ; on which, how- 

 ever, the condyle is more sharply defined from the trochlea. 

 In the human skeleton, the internal lip of the trochlea 

 descends lower than the external ; and also lower than the 

 condyle. In the bear, the cat, and the dog, it is the same. 

 In the ox and the sheep, the condyle is lower than the 

 trochlea, but only very little lower. In the horse the 

 arrangement is still the same, but a little more accentuated. 

 On the lateral parts of this extremity we find : internally, 

 a prominence, the epitrochlea ; and, externally, another, 

 the epicondyle. It is from this latter that the crest arises, 

 which, passing upwards, forms the posterior limit of the 

 groove of torsion. 



The two prominences, which we have just described from 

 a general point of view, present special arrangements which 

 it is necessary to point out. When we examine the form 

 of the outline of the inferior extremity of the humerus in 

 man, the bear, the cat, the dog, the ox, and the horse, we 

 find in following this order that the extremity tends to 

 become narrow transversely, and that the epicondyle and 

 the epitrochlea are less and less prominent on the external 

 and internal aspects respectively. These two processes, 

 indeed, project backwards ; the epitrochlea always remain- 

 ing more developed than the epicondyle. Because of this 

 projection backwards, the cavity situated on the posterior 



