36 



SHOULDER BLADE 



for or serve to push along the rapidly-moving body. Stronger 

 fixation is therefore a greater necessity posteriorly than anteriorly. 

 In any case, whatever the explanation, this important difference 

 exists. 



The shoulder-blade of mammals is as a rule a much-flattened 

 bone with a ridge on the outer surface known as the spine ; 



Fig. 25. —Right scapula of 

 Dog [Canis familiaris). 

 X |. rt, Acromion ; af, 

 prescapular fossa ; c 

 coracoid ; cb, coracoid or 

 anterior border ; ess, in- 

 dicates the position of 

 the coraco-scapnlar su- 

 ture, obliterated in adult 

 animals by the complete 

 ankylosis of the two 

 bones ; gb, glenoid or 

 posterior border ; gc, 

 glenoid cavity ; pf, post- 

 scapular fossa ; s, spine ; 

 ss, suprascapular border. 

 (From Flower's Oste- 

 ology.) 



Fig. 26. — Right scapula of 

 Red Deer {Cerims elaplucs). 

 X ^. a, Acromion ; af, an- 

 terior or prescapular fossa ; 

 c, coracoid ; gc, glenoid 

 cavity ; ^;/, postscapular 

 fossa ; ss, partially ossi- 

 fied suprascapular border. 

 (From Flower's Osteology.) 



this ridge ends in a freely -projecting process, the acromion, 

 from which a branch often arises known as the metacromion. 

 This gives a bifurcate appearance to the end of the ridge. The 

 spine is less developed and the scapula is narrower in such 

 animals as the Dog and the Deer which simply run, and whose 

 fore-limbs therefore are not endowed with the complexity of 

 movement. seen, for instance, in the Apes. 



It has been pointed out that the area which lies in front of 



