ARTIFICIAL SELECTION 165 



greatest care of that specimen. Having reached the 

 suitable age, he used it for breeding purposes, and by 

 successive skilfully selected pairings he succeeded, 

 after several years, in obtaining a healthy flock, 

 but with the same excellent wool of that sickly, 

 rickety ram. 



Robert Bakewell,in Leicestershire, was the creator 

 of the breed of Dishley sheep. He reduced the 

 carcase of this sheep, and in exchange increased its 

 flesh and fat considerably, so that when one of 

 these animals falls it is necessary to raise it. 

 They add to these qualities, acquired artificially, a 

 great propensity for fattening, that is, they attain 

 the maximum development in the shortest possible 

 time. 



In the Durham breed of cattle, the brothers 

 Colling have achieved the same result, obtaining 

 veritable flesh-making machines. 



The thoroughbred horse is a wonderful creation 

 all the more if compared, as an artificial production, 

 with those already cited. Here selection has been 

 entirely on opposite lines ; in it the two extremes 

 of the breed of cattle on the one hand, and the 

 single -hoofed animal on the other, are represented. 



Thus it is demonstrated how life yields to 

 modification by the hand of man to form two kinds 

 of energy, in one of which figure the flesh-pro- 

 ducers, in the other, specimens of great speed. 



