OSTEOLOGY 137 



fectly flat in some cases. The teres major originates upon 

 the gleno-vertebral angle, but it has no appreciable effect 

 upon it. The same may be said of the occipitoscapularis, 

 arising from the vertebral border of the supraspinous fossa, 

 and the rhomboideus posticus, in almost the same relation 

 to the infraspinous fossa. From the remainder of these two 

 fossae originate respectively the two muscles after which 

 they are named. The scapula narrows ventrad to form the 

 neck, the cranial border of which is known as the supra- 

 scapular notch. Upon the ventral portion of this originates 

 the omoh3'oid muscle. 



The spine of the scapula occupies a position roughly 

 central upon its lateral surface. At its vertebral termination 

 there is a small triangular area over which passes the apo- 

 neurosis of the trapezius. As it passes cranio-ventrad the 

 spine is bent caudo-ventrad, which change in direction is 

 influenced by the pull of the spinodeltoid attached to the 

 caudo-ventral border, and the acromiotrapezius upon the 

 cranio-dorsal border. It should be noted that the stress of 

 the latter is against the inclination of the spine. In addition, 

 the spinotrapezius is inserted upon the dorsal third or fourth 

 of the lateral border of the spine. Upon the remainder of 

 the more dorsal aspect originates a separate head of the supra- 

 spinatus muscle. The border of the spine ends ventrad in 

 the metacromion, a process formed by the sharp bending 

 of the spinal border, apparently influenced by the spino- 

 deltoid, atlanto-scapularis, and possibly by the teres minor 

 beneath it. The spinal border then passes dorsad and 

 shghtly mediad, ending in the acromion. Upon this ventral 

 border between the metacromion and acromion is part of the 

 origin of the clavo-acromiodeltoid. The latter muscle, and 

 articulation of the acromion with the clavicle, results in some 

 individual variation in the precise shape of this process and 

 its border, but in nothing that can be considered as sub- 

 generic. The ventral third or less of the spine is free from 



