SCAPULA. 



125 



prominent convexity, whilst towards the axillary border is a deep groove, which 

 runs from the upper towards the lower part. The inner three-fourths of this 

 surface afford attachment to the Infra-spinatus muscle ; the outer fourth is only 

 covered by it, without giving origin to its fibres. This surface is separated from 

 the axillary border by an elevated ridge, which runs from the lower part of the 

 glenoid cavity, downwards and backwards to the posterior border, about an inch 



Fig. 85. Left Scapula. Posterior Surface or Dorsum. 

 Cora co i^ 



above the inferior angle. This ridge serves for the attachment of a strong apon- 

 eurosis, which separates the Infra-spinatus from the two Teres muscles. The 

 surface of bone between this line and the axillary border is narrow for the upper 

 two-thirds of its extent, and traversed near its centre by a groove for the passage 

 of the dorsalis scapulne vessels ; it affords attachment to the Teres minor. Its 

 lower third presents a broader, somewhat triangular surface, which gives origin 

 to the Teres major, and over which glides the Latissimus dorsi ; sometimes the 

 latter muscle takes its origin by a few fibres from this part. The broad and narrow 



