198 



SKELETON OF THE DOG 



unites with the rest of the bone at six to eight months. The shoulder has a great 

 range of movement on the chest walL 



The hiunerus is relatively very long, rather slender, and has a slight spiral 

 twist. The shaft is somewhat compressed laterally, especially in its proximal two- 

 thirds; this part is curved in varying degree, convex in front. The deltoid tuber- 

 osity has the form of a low ridge, and it is continued by a crest which runs up- 

 ward and backward and bears a tubercle on its proximal part. Another hne runs 

 from it down the anterior aspect and forms, the medial boundary of the very shallow 

 musculo-spiral groove. The nutrient foramen is about in the middle of the posterior 

 surface. A slight elevation on the proximal third of the medial surface represents 

 the teres tubercle. The head is long and strongly curved from before backward. 

 The neck is better marked than in the horse. The undivided lateral tuberosity is 

 placed well forward and extends little above the level of the head. The medial tu- 



Cartilage 



Cartilage 



Supra- 

 spinous 1' 

 fossa 



Xeck 



Tuhcr 

 scapulas ^ | Glenoid cnvity 



Acromion 



Fig. 2Hi. — Left Scapula of Dog; Lateral View. 



Posterior 

 border 



scapula: — ^ f \ 



Glenoid cavity 



Fig. 217. — Right Scapula of Dog; Medial View. 



berosity is small. The intertuberal or bicipital groove is undivided and is displaced 

 to the medial side by the extension forward of the lateral tuberosity. The distal 

 end bears an oblique trochlear articular surface for articulation with the radius and 

 ulna, the lateral part of which is the more extensive and is faintly grooved. The epi- 

 condyles are prominent. The coronoid and olecranon fossee often communicate 

 through a large supratrochlear foramen. The proximal end unites with the shaft 

 at about one year, the distal at six to eight months. 



The two bones of the forearm are relatively long and articulate with each other 

 at each end in such a manner as to allow of slight movement. A narrow inter- 

 osseous space separates their shafts. The radius is flattened from before back- 

 ward and increases in size distally. The shaft forms two curves, so that it is con- 

 •\'ex dorsallj' and medially. The dorsal surface is convex in both directions and is 

 marked in its distal half by a groove for the oblique extensor of the carpus. The 

 volar surface presents the nutrient foramen in its proximal third, and bears a rough 



