390 PRINCIPLES OF STOCK-BREEDING. 



In the improvement of all domesticated varieties 

 that are not intended for work, selections are made on 

 a different basis, that is not favorable to the develop- 

 ment of the greatest constitutional vigor. Take the 

 meat-producing breeds, for example, and examine care- 

 fully the tendencies of the process of improvement. 

 Early maturity is required, and a liberal system of 

 feeding is practised ; the wants of the animal are anti- 

 cipated, and it is protected from the inclemencies of 

 the seasons. The animal must have a quiet disposi- 

 tion to be a good feeder, and the treatment it receives 

 tends to promote a habit of " masterly inactivity." 



The best quality of flesh and a large proportion of 

 choice parts are desirable, and a certain refinement of 

 the system is the result of the efforts to obtain them. 



Thus, step by step as we trace the process of im- 

 provement, we find the required conditions are unfa- 

 vorable to the development or retention of constitu- 

 tional vigor. 



It is asserted by Prof. Tanner that, in the im- 

 proved breeds, " the lungs and liver are found to be 

 considerably reduced in size when compared with 

 those possessed by animals having perfect liberty ; " x 

 and this he attributes to the lack of active exercise, 

 which is required for the symmetrical development of 

 the system. 



The breeder must not lose sight of the tendency 

 to undesirable variations in making his selections, or 

 the defects of his stock may impair or even overbal- 

 ance the advantages arising from their good qualities. 



1 " Transactions of the Highland Agricultural Society," 1859-'61, p. 

 322. 



