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XXVII. 



SOME YAliTATIONS IN THE SKELETON OF THE DOMESTIC 

 HORSE AND THEIR SIGNIFICANCE. 



By major p. EASSIE, D.S.O. 



[communicated by nu. k. f. schauff, PH.n., b.sc] 



(Platks XVI.-XX.) 

 [Rend December 21, 1909. Ordered for Publication, January 11 ; Published, March 8, 1910.] 



My first object will be to show that the skeleton of the domesticated liorse 

 frequently gives proof of deterioration from the type of the skeleton of the 

 wild horse. In order to make this clear, I shall first consider the latter, 

 and show liow this deterioration manifests itself. A group of qualities 

 essential to the horse are affected by the deterioration of tlie skeleton, such 

 as strength, vitality, nervous energy, and stamina; all of which are normally 

 attributes of the wild animal. Certain variations in tlie skeleton will then 

 be discussed ; and I shall endeavour to show that these are apparently 

 transmitted as independent hereditary characters. 



Three variations in the skeleton may be considered : — 



1. The relative length of the spine, including the head. 



2. The relative length of the arm. 



3. The relative length of the thigh. 



One of my arguments is that tlie short spine is a racial character in the 

 Arab ; and that it is transmitted in the first cross of the Arab. I shall also 

 attempt to show that the relative shortness respectively of the arm and of the 

 thigh are ultimate phases in evolution ; that they determine qualities in the 

 horse of the utmost economic value, namely, balance of the body on tlie 

 supporting limbs, and speed ; and that both are apparently separate 

 dominant characters as regards heredity. Finally " action " in the horse 

 will be considered, and how it is dependent on the foregoing characters of the 

 skeleton. 



Before entering on the discussion of the subject, I ought briefly to state 

 the circumstances under which the ideas contained in this paper have been 

 formed. I was first led to study the subject by some remarks upon 

 degeneration in the horse made to me by an officer of my own service^ about 



' Major, now Colonel Bleiikinsop, D.S.O. 

 SCIBNT, PKOC. K.D.S., VOL. XII., KG. XXVIJ, 3 F 



