210 PRINCIPLES OF STOCK-BREEDING. 



cessful admixture ; so that, in the course of time, by 

 the aid of selection and careful weeding, it is practi- 

 cable to establish a new breed altogether. 1 . . . Let us 

 conclude," he then says, "by repeating the advice 

 that, when equal advantages can be attained by keep- 

 ing a pure breed of sheep, such pure breed should 

 unquestionably be preferred ; and that, although cross- 

 ing for the purposes of the butcher may be practised 

 with impunity, and even with advantage, yet no one 

 should do so for the purpose of establishing a new 

 breed, unless he has clear and well-defined views of 

 the object he seeks to accomplish, and has duly stud- 

 ied the principles on which it can be carried out, and 

 is determined to bestow for the space of half a life- 

 time his constant and unremitting attention to the 

 discovery and removal of defects." a 



From the variety of improved breeds that can now 

 be obtained, adapted to almost every variety of climate 

 and system of management, it cannot be desirable to 

 attempt the formation of a new breed, as any special 

 qualities that may be required under particular cir- 

 cumstances can be more readily obtained by a modifi- 

 cation of the characteristics of some existing breed 

 that approximates in its qualities to the proposed 

 standard. 



As cross-breeding among cattle, sheep, and swine, 

 can only be recommended for the production of ani- 

 mals intended for the butcher, it may be well to con- 

 sider some of the advantages arising from its judicious 

 practice for this purpose. 



1 Journal of the Royal Agricultural Society, vol. xx., p. 311. 

 3 Loc. cit., p. 813. 



