THE BONES OF THE UPPER LIMB 



183 



The coracoid process of man represents the coracoid bone of 

 monotremata and lower vertebrates. 



The scapula derives its blood-supply from the dorsalis scapulae, 

 suprascapular, and posterior scapular, arteries. 



Articulations. — By its acromion process with the outer extremity 

 of the clavicle, and by the glenoid cavity with the head of tfee 

 humerus. 



Structure. — ^The scapula is a flat or tabular bone, and is composed 



Subcoracoid Epiphysis, Appears at 

 loth Year, and joins at 16 



Apical Epiphysb. Appears about 



i8th Year, and joins about 25. 



Accessory Coracoid. Appears about 



puberty, and soon joins. 



Appears about the i6th Year, 

 and joins about 25 



Coracoid Element. Appears ic ist Year, 

 and joins at 15 

 \ Appear about the i6th Year, 

 ' and join Spine about 25 



~- . Line of junction of 

 Coracoid Element 



Appears about the i6th Year, 



and joins about 25 



Fig. 103. — Ossification of the Scapula. 



of two tables of compact bone. In the head, axillary border, 

 inferior angle, and processes there is cancellated tissue between 

 the two tables, but in the central portions of the supra- and infra- 

 spinous fossae there is none, and the two tables coalesce, so that 

 the bone is very thin and transparent. 



Varieties. — (i) Suprascapular foramen. (2) Fenestrated scapula, pre- 

 senting one or more perforations in the subscapular fossa. (3) Separation of 



