266 BLO OD, S YMME TRY AND COMPENSA TIONS. 



which have been bred in a hot, dry climate. The speed of 

 the thoroughbred is the resuk of careful selection in breeding, 

 by which, not only has the best form of conformation been 

 obtained, but also the most suitable kind of nervous organisa- 

 tion. The effect of heredity is specially shown in the working 

 of the nerves, which regulate the exhibition of all muscular 

 force. Although they can in no way increase the actual 

 strength of a muscle, its failure or success in putting forth its 

 full power, and also its speed of contraction are dependent on 

 them. Hence, two horses of identically the same "make 

 and shape " (if such a thing were possible) might differ widely 

 in pulling power, handiness, or speed, on account of a want of 

 similarity in their nervous systems. We see this fact well 

 marked among men, in whom uncommon quickness and great 

 dexterity of muscular movement is often inherited. The 

 speed, then, obtained from "blood," independent of confor- 

 mation, may be regarded as an outcome of heredity. In 

 judging, therefore, by a horse's conformation, of his suitability 

 to any particular kind of work, we should take into careful 

 consideration all the " blood " points which he may possess. 

 I may mention that the fact of a horse having Arab blood 

 in his veins, is, in itself, no reason for our inferring that he 

 has a good "turn of speed;" for Arabs, though charming 

 hacks and admirable light cavalry troopers, are not race- 

 horses. 



It is noteworthy that thoroughbred stock which are 

 allowed (as they often are in the Colonies) to run wild, say, up 

 to four or five years old, before they are taken up, and which 

 are then put to ordinary labour, lose in a great measure the 

 blood-like appearance they might have possessed, had they 

 been handled early and put into training in the usual way. 



