58 CONFORMATION AND ITS DEFECTS 



force of the impulses transmitted to it in progression by the hind 

 extremities is greatly diminished. It is for these reasons that sway-hacked 

 animals lack the power and jiace of others more perfectly constructed. 



This condition, like the roach -hack, may result when horses are sub- 

 jected to hard work and heavy burdens during their colthood. It is also 

 developed in very old animals, whose back muscles, becoming wasted and 

 weak, fail in their support of the spine and the weight imposed upon it. 



In considering this defect it must not be overlooked that hollowness of 

 the back is in many cases more apparent than real. Horses with lofty 

 carriage, prominent withers, and high croup often give the appearance of 

 hollowness, although the back may be anatomically and physiologically 

 perfect, and a similar false appearance will result if the spines surmounting 

 the vertebrte in this region are exceptionally short and the muscles slightly 

 developed. 



In any case hollowness of the back, whether real or only apparent, is 

 an eyesore. In the former case it is a serious defect as well, insomuch as 

 it diminishes the capacity to race, or jump, or carry weight. Horses thus 

 formed are more especially adapted for harness purposes. 



THE CROUP 



The croup comprises that part of the body situated between the loins 

 and the setting on of the tail. It extends on each side as far as the upper 

 part of the thighs aud buttocks. The pelvis, which together with the sacrum 

 forms the bony base of this region, although entering into the formation of 

 the trunk, must nevertheless be regarded as parts of the hind extremities 

 corresponding with the scapulse or shoulder-blades of the fore-limbs. 



The coxee or uppermost bones of the posterior limbs are united 

 together below, and joined to the sacrum or terminal portion of the spine 

 above. By this arrangement a firm aud compact union is effected between 

 the leg and the trunk, so that the impulses from behind may be imparted 

 to the entire body, through the articulation of the femur or thigh-bone 

 with the pelvis. 



To the horse as a living motor the construction and development of 

 this region is of supreme importance. 



In galloping, jumping, rearing, as well as in draught, those vigorous 

 efforts which enter into the highest expression of speed and power are 

 mainly produced by the action of the muscles of the croup on the upper 

 and lower thigh. How ftir that action may be effective in the one case or 

 the other will depend upon the mechanical arrangement of the parts. 



Length and width are qualities to which the croup owes its chief beauty 



