BONES OF THE THORACIC LIMB 



177 



foramen is on the posterior surface below its middle. The head is more strongly 

 curved and the neck better marked than in the horse or ox. The lateral tuber- 

 osity is very large and extends upon the front of the extremity. It is divided into 

 two high prominences by a wide deep groove. There is a third eminence below 

 and laterally for the attachment of the supraspinatus muscle. The intertuberal or 

 bicipital groove is at the front of the medial side; it is undividetl and is almost con- 

 verted into a canal. The lateral groove on the distal articular surface is so shallow 

 as to give the appearance of two condyles of similar size. The olecranon fossa is 

 very deep, and the plate of bone which separates it from the coronoid fossa is thin 

 and sometimes perforated. The proximal end unites with the shaft at three and a 

 half years, the distal at one year. 



a, Anterior angle; 



Fig. 184. — Left Scapi'la of Pig; Medial View. 

 b, posterior angle; c, anterior border; d, posterior border; e, neck; /, vascular groove; 

 cavity; h, tuber scapulae; 1, subscapular fossa; 2, serratus area; 3, cartilage. 



, glenoid 



The radius is short and narrow, but thick. The shaft increases in size distally. 

 The greater part of the volar surface is in apposition with the ulna; this part is 

 marked by a vascular furrow which runs distally from the proximal interosseous 

 space, and has the nutrient foramen at its proximal end. The radial tuberosity is 

 represented by a rough area. The distal end is relatively large. Its carpal sur- 

 face consists of concavo-convex facets for the radial and intermediate carpal bones. 

 There is a wide shallow groove on the middle of the front. The proximal end fuses 

 with the shaft at one year, the distal at three and a half years. 



The ulna is massive. It is much longer and considerably heavier than the 



radius. The shaft is curved. The dorsal surface is convex and most of it is rough 



and attached to the radius by the interosseous ligament. There is a smooth area 



on the upper third, which concurs with the radius in forming the proximal inter- 



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