THE UPPER LIMB IN MAN. 



233 



is inclined outwards and forwards against the axis of the 

 shoulders, and meets it in the glenoid cavity. The 

 shaft of the clavicle inclines much more backwards 

 against the shoulder axis, passes above it, and abuts 

 against the acromion, above the glenoid cavity. 

 The axis of the shoulder is therefore at right angles, 

 not only to the axis of the spine, but also to that 

 of the haunch (Fig. 1). 



b. On the other hand, the axis of the shoulder 

 of the animal is oblicjue, not only towards the 

 hrenial aspect, but also towards the cephalic ex- 

 tremity of the axis of its spinal column ; that is, 

 in an opposite direction to the obliquity of its 

 haunch, which is oblique towards the coccygeal 

 extremity of the spinal axis (Figs, 2, 3, 4, 5). The 

 quadrupedal scapula is so oblique that the anterior 

 ends of the two bones approach one another ante- 

 riorly. These obliquities are of importance in Fif } 

 the animal economy. In the shoulder of the *• Axis of trunk. 



J 2. Axis of hauncli. 



horse, for example, the more oblique the scapula 3 - Axis of shoulder 

 the better adapted is the animal for speed. The scapula is 

 the chief bone of the shoulder, as both the coracoid and 

 clavicle may for the most part disappear. 



Pig. 2. 

 Outline diagram of a Quadruped. 



Pig. 3. 

 Outline diagram of a Monkey when In the tort- 



Zoiit.-il po .il inn. 



c The anatomical conditions which determine the antero- 

 posterior and transverse obliquities respectively of the 

 shoulder in the animal are : — 



l i. For the antero-posterior obliquity — the upward curv- 



