DIRECTION OF THE BACK AND LOINS 57 



appearance of slackness, hence the common expression, "slack in the 

 loin ". Horses so constructed are said to " want a rib ". 



DIRECTION OF THE BACK AND LOINS 



The line described by these regions will be found to vary to a con- 

 siderable extent in ditierent individuals. In some it is straight, in others 

 more or less curved in an upward or downward direction. 



A straight back is the one universally recognized by judges as com- 

 bining the greatest measure of power with the most perfect freedom and 

 scope of action. 



An upward curve of the back is described as a roach hack (Plate VIII). 

 Most WTiters appear to agree that this condition is specially adapted 

 to the purpose of bearing weight, l)ut it presents several important 

 disadvantages. In animals so constructed the back is shortened by the 

 upward curvature, and the great spinal muscles are said to be wanting in 

 development — two conditions distinctly opposed to great range and rapidity 

 of movement. Captain Hayes points out that as a rule in these cases the 

 " chest is flat-sided", but Goubaux and Barrier affirm that it is " incorrect 

 to associate this condition with flat ribs and a narrow chest". Between 

 the two statements there is a medium which best accords with the experi- 

 ence of the writer, and it may lie expressed by saying that sometimes 

 roach-backed horses are flat-sided. 



In both light and heavy draught-horses this defect is sometimes 

 acquired by being forced into heavy and prolonged work at an early 

 period of life, while the bones and ligaments of the spine are imperfectly 

 developed. Horses thus deformed are said to be " pulled out of shape ". 

 Whether congenital or acquired, however, this arching of the back is 

 seldom found to interfere with the services of the shaft - horse whose 

 work does not call for rapid locomotion. It is an eyesore, and as such 

 materially depreciates the value of the animal in wdiich it occurs. 



The back is liollotv or saddle-hacked when it describes a downward 

 curve (Plate VI). Here the bones of the spine are depressed, either as the 

 consequence of some disturbance in the course of development, or from 

 relaxation of the ligaments by which they are united and supported. In 

 this type of horse the vertebrae lack firmness of union, the back as a whole 

 is wanting in rigidity and power of resistance, with the result that the 

 weight, instead of being borne by the bones, is in too great part supported 

 by the connecting ligaments, which, when overburdened, yield, and 

 by so doing add to the existing defect. Not only is the superimposed 

 weight badly sustained, but, owing to want of solidity in the spine, the 



