

DEVELOPMENT AND ITS RESULTS. 15 



tected from any struggle for existence 

 that is, they are kept in comfort and fully 

 supplied with suitable food, but otherwise 

 under natural conditions. By such system- 

 atic breeding any cross-blood in the herd 

 is practically eliminated in a few genera- 

 tions ; and by selecting the most vigorous 

 animals and developing their progeny under 

 the most favourable conditions, a full expres- 

 sion of type is evolved. 



So treated, the herd of the successful 

 breeder will in a few generations approxi- 

 mate, perhaps as closely as it ever will, to a 

 full expression of the type. There were as 

 good specimens of our pedigreed breeds of 

 cattle fifty years ago as there are to-day. 



Selective breeding has been steadily pros- 

 ecuted for three-quarters of a century, and 

 has brought about a higher average ex- 

 pression of type among cattle generally than 

 formerly obtained, but there has been no 

 tendency to specific variation in type. On 

 the contrary, the invariable experience has 

 been that the longer selective breeding is 

 pursued, the more firmly established becomes 

 the family expression of a herd, and the more 

 forcibly do the parents stamp the family like- 

 ness on their progeny. 



But with improved expression of type the 



