250 



THE SHOULDER GIRDLE. 



[CHAP. 



postscapular fossa is much developed, and the suprascapular 

 border is long, straight, and forms an acute angle with the 

 glenoid border. At the junction of the coracoid border of 

 the scapula with the coracoid bone, there is a more or less 

 well-marked notch (cor aco- scapular notcJi). The spine is 

 well developed, and the acromion large and curved forwards 

 near its extremity. 



IG. 77. The human sternmn and right shoulder girdle at a very early period of 

 development (from an embryo 5^ inches long) after Parker, \\. The dotted parts 

 are still cartilaginous ; the inner surface of the sternum and clavicle, and outer 

 surface of the scapula are represented, ost omosternum, afterwards developed 

 into the interarticular fibre-cartilaginous disk ; pc precoracoid of Parker ; cl shaft 

 of the clavicle ; mss mesoscapular segment of Parker ; a acromion ; c coracoid ; 

 gc glenoid cavity of scapula ; gb glenoid border ; cb coracoid border ; of anterior,, 

 or ''supraspinous," fossa ; pf posterior, or *' infraspinous," fossa ; JJ suprascapular 

 border. 



The coracoid forms a well-marked hook-like process ; it 

 contributes a very small part to the glenoid fossa, and unites 

 with the scapula about the time of puberty. 



The clavicle (Fig. 77, cl) is a strongly-developed sigmoid 

 bone, remarkable for the very early age at which it com- 

 mences to ossify, in fact before any other bone of the body. 

 The outer extremity is, in the young state, tipped with 



