SUPERIOR FACE OF THE BODY. 113 



first edition of this book we have wrongfully considered that the 

 height of the withers should be viewed from their elevation in relation 

 to the croup and the adjacent parts. 



In view of the criticism which this opinion has received, we recog- 

 nize to-day that the relative height of the croup is not germane to the 

 subject which we now have under consideration, but to the respective 

 heights of the anterior and the posterior extremities of the bodv. We 

 will discuss this in the chapter on proportions, as to the dimensions 

 of the body as a whole (see Height and length of the body ; Horses high 

 and low in front). 



By the height of the withers should be meant, therefore, only the 

 height of the eminence formed by this part of the body above the 

 adjoining regions, such as the shoulders, the back, and the superior 

 border of the neck. By extent we are to understand the total dimen- 

 sions of the withers antero-posteriorly ; in a word, the degree in which 

 it is prolonged towards the region of the back. This circumstance, de- 

 pendent in a large measure upon the length and inclination of the 

 spinous processes, necessarily enables the latter to play the part of the 

 long arms of the levers of the extensor muscles of the vertebral col- 

 umn, and is therefore a favorable condition for the development of 

 speed. 



The height or elevation of the withers depends, on the contrary, 

 upon several diverse causes, which we must determine. Among them 

 we mention : 



a. The well-defined form, or the thiekness, of which we have already 

 spoken, which concur to modify the obliquity of the lateral faces in 

 consequence of either the lowness or the prominence of the entire 

 region, as the case may be. 



6. The length and obliquity of the shoulder, which tends to cover, 

 to an extent more or less considerable, the sides of the apophyses 

 of the first dorsal vertebra. 



c. The absolute length and vertical direction of these processes, 

 which, by their summits, exceed to a variable extent the border of the 

 scapular cartilages. 



d. Finally, the mode of suspension of the thorax between the anterior 

 members, the effect of which is to produce a more or less marked pro- 

 jection of the summits of the spinous processes above the superior 

 border of the shoulders. 



The age, the sex, and the state of the genital organs have equally 

 their influence. Poorly delineated in the foal and the young animal, 

 the withers become more prominent towards the fifth, sixth, or seventh 



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