68 CATTLE-BREEDINa. 



condition the production of milk rich in butter 

 fats. The Holstein by a similar treatment 

 directed to the production of milk containing 

 a large amount of cheese-making products 

 (caseine) were carried to another special end. 

 The Hereford was driven to a high stage of beef 

 production under a specialized treatment. In 

 each case the intense stretching of the line in 

 one direction produced a counter effect by a 

 partial loss of neglected qualities; of beef pro- 

 duction in the Jersey, of that and also of fats 

 in the abundant and caseine-rich milk of the 

 Holstein; of milk production in the Hereford. 

 A different course was early adopted by, the 

 breeders of the Short-horn (Durham) and they 

 have always sought to develop this breed by 

 careful selection to a high excellence as beef 

 and dairy cattle, neglecting neither meat, milk, 

 butter nor cheese-making qualities, and care- 

 fully guarding against the atrophy of any de- 

 sirable quality. 



"We have good grounds for believing," says 

 Mr. Darwin, "that the influence of changed 

 conditions accumulates, so that no effect is 

 produced on a species until it has been exposed 

 during several generations to continuous culti- 

 vation or domestication. Universal experience 

 shows us that when new flowers are first intro- 

 duced into our gardens they do not vary; but 

 ultimately all, with the rarest exceptions, vary 



