190 TRAINING AND RACING. 



tion of blood towards them, occasions an increase in the 

 nutrition ; so that a large amount of new tissue is deve- 

 loped, and the muscles augment in size and vigour. 

 This is true, not only of the whole muscular system 

 when equally exercised, but also of any particular set of 

 muscles which is more used than another. Of the former, 

 we have an example in those who practise a system of 

 gymnastics adapted to call the various muscles alike into 

 play ; and of the latter, in the limbs of individuals who 

 follow any calling that habitually requires the exertion 

 of either pair, to the partial exclusion of the other, as 

 the arms of the smith, or the legs of the opera-dancer. 

 But this increased nutrition cannot take place unless 

 an adequate supply of food be afforded ; and if the 

 amount of nutritive material be insufficient, the result 

 will be a progressive diminution in the size and power 

 of the muscles, which will manifest itself the more 

 rapidly as the amount of exertion, and consequently the 

 degree of waste is greater. Nor can it be effected if 

 the exercise be incessant, for it is during the intervals of 

 repose that the reparation of the muscular tissue occurs ; 

 and the muscular system, like the nervous, may be worn 

 out by incessant use. The more violent the action, the 

 longer will be the period of subsequent repose required 

 for the reparation of the tissue." 



From this we see that while giving the horse the 

 exercise necessary to develop those muscles which are 

 used in galloping, we should attend to his due nutrition ; 

 should afford him the rest indispensable for the repair 

 of tissue, and should preserve around him the conditions 

 that are most conducive to health. 



