THE FOEE LIMB 



193 



the outlet behind. The j^elvic cavity of the mare is larger than that of 

 the horse in every direction, but especially from side to side. The floor of 

 the female pelvis is distinctly wider than that of the male animal. 



THE FORE LIMB 



The fore extremity is made up of twenty bones : the scapula, humerus, 

 radius, and ulna above the knee; the scaphoid, lunar, cuneiform, pisiform, 

 trapezoid, os magnum, unciform in 

 the knee; and the large and two 

 small metacarpal bones, two sesa- 

 moid bones, the os suffraginis, os 

 coronte, os naviculare, and os pedis 

 below the knee. 



Scapula (figs. 296, 297).— This 

 is the uppermost bone of the fore 

 limb, a flat triangular segment 

 placed on the side of the chest, 

 where it takes an oblique direction 

 downward and forward. Its base 

 is turned upward, and its apex con- 

 curs with the humerus to form the 

 shoulder-joint. A broad flat piece 

 of cartilage is attached to its upper 

 border, and gives increased length 

 to the bone, hence it is termed car- 

 tilage of i^t'olongation, or scapular 

 cartilage. The scapula has three 

 angles : 1 , cervical, nearest the 

 neck; 2, dorsal, nearest the back; 

 3, humeral, at the point of the 

 shoulder. The last presents a 

 shallow oval cavity, which receives 

 the rounded head of the humerus 

 to form the shoulder-joint. Im- 

 mediately above it, in front, is a large rough curved ofl"shoot of bone,, 

 the coyacoid i^rocess, which gives attachment to important muscles. 



The outer surface of the bone is divided into two unequal parts by 

 a bony ridge or spine. This bone is united with the trunk by muscles 

 only. It has no synovial articulation or joint connection as in the hind 

 liml). 



Fig. 296.— Scapula (Outer Surface) 



1, 1 Spine of the Scapula. ^ Coracoid Process. 



^ Glenoid Cavity for Articulation of Humerus. ■* Dorsal 

 Angle. ^ Cervical Angle. ^ Cartilage of Prolongation- 



47 



