LEG (SECOND THIGH) 85 



of the hip-joint, a condition, as we have seen, which has no parallel 

 in the fore-limb. 



Thigh. — The thigh is the uppermost of the free -moving segments 

 of the hind extremity. Viewed from without, it embraces that portion 

 of the quarter enclosed within the limits of the croup and haunch above, 

 the flank in front, the buttock behind, and the stifle and leg below. It 

 has for its ])ony base the femur or thigh-bone, one end of which unites 

 with the pelvis to form the hip-joint, and the other articulates with the 

 tibia and patella to form the stifle. 



The importance of the thigh in the function of locomotion is indicated 

 by the mass of the muscles which enter into its formation. In no other 

 region of the locomotory columns do these organs reach such volume and 

 power. For the most part the forcible impulses by which the body is 

 driven forward in the various modes of progression originate in the muscles 

 of the thigh, and as an element in ec|uiue conformation this division of the 

 body deserves the fullest recognition. 



Not the least important consideration afi"ecting this region is that it 

 should be w^ell directed, neither inclined unduly forward nor backward. 

 When the former inclination jarevails the leg as a w'hole is brought too 

 much under the body, whereby its range of forward movement is curtailed, 

 and its power is in some degree expended in raising the trunk at the expense 

 of its propelling force. With a too backward inclination the limbs are 

 carried too far to the rear, in which case the horse is said to " leave his legs 

 behind him ". It is also important in race-horses, hunters, and chasers that 

 the inferior extremity of the thigh should be outwardly inclined, so as to 

 clear the trunk when moved forward in the act of galloping and jumping. 



Viewed in profile, the thigh should be broad and exhibit ample mus- 

 cular development from top to bottom, or, as it is expressed, be " well let 

 down ". Seen from behind, it should be thick in proportion ; any lightness 

 in this dimension gives to the part a lean, "sj)lit-up" appearance, which is 

 always a sign of weakness. [Plate VIIL] 



LEG (SECOND THIGH) 



That segment of the hind-limb situated between the thigh and the hock 

 is properly designated the leg ; more commonly it is spoken of as the second 

 thigh. Two bones enter into its basement structure, the tibia and the 

 fibula. The former is much the larger and more important of the two, and 

 supplies well-nigh all the conditions pertaining to the mechanism of the 

 region. 



It is a requirement of all fast motors that the leg should be long, thus 



