THE HUMERUS 



79 



antero-externally, and consists of two parts; the anterior part forms the outer 

 boundary of the bicipital groove and gives attachment to the external branch of 

 the supraspinatus nmscle; the posterior part gives attaclunent to the short inser- 

 tion of the infraspinatus, while its outer surface is coated with cartilage, over which 

 the chief tendon of the same muscle passes to be inserted into a triangular facet on 

 the outer aspect of the anterior part. The internal tuberosity (Tuberculum minus) 

 is less salient, and consists of anterior and posterior parts; the anterior part forms 

 the inner boundary of the bicipital groove, and furnishes insertion to the inner 

 branch of the supraspinatus above, and the posterior deep pectoral muscle below; 



Bicipital 

 groove 



Internal tuberosity 



Intirnnl tubercle 



Coronoid fossa 

 Internal epicondijle 



External tuberosity 



Deltoid tidxrosity 



Musculo-spiral groove 



External condyloid crest 



External condyle 



Internal condyle 

 Fig. 47. — Left Humerus of Horse, Anterior View. (After Schmaltz Atlas d. Anat. d. Pferdes.) 



the posterior part gives attachment to the subscapularis muscle. The bicipital 

 or intertubercular groove (Sulcus intertubercularis) is situated in front; it is 

 bounded by the anterior parts of the tuberosities, and is subdivided by an inter- 

 mediate ridge. The groove is covered in the fresh state by cartilage, and lodges 

 the tendon of origin of the biceps brachii muscle. Just below the intermediate 

 ridge is a small fossa in which several foramina open. 



The distal extremity has an oblique surface for articulation with the radius 

 and ulna, which consists of two condyles of very unequal size, separated by a ridge. 

 The internal condyle (Condylus medialis) is much the larger, and is crossed by a 

 sagittal groove, on the anterior part of which there is usuall}^ a synovial fossa. Pos- 



