LINE BREEDING. 109 



out of all control. Its kinship to in-and-in 

 breeding thus becomes more noticeable; in- 

 deed, it is perhaps not too much to say that it 

 is a modified form of that practice, and that 

 most of those who practice it are in more or 

 less close sympathy with the theory of in-and- 

 in breeding, and have only departed from it 

 just so far as they were driven by the fears of 

 physical decay. 



The aim of line breeding, as has already been 

 pointed out by implication, is to secure and 

 maintain a high degree of identity of blood, 

 the object being to obtain as nearly as possible 

 exact uniformity in the herd. It is quite pos- 

 sible to attain a most perfect conformity of 

 type in this way. Herds long bred on this 

 principle become more and more reduced to a 

 single type. I say reduced advisedly, and here 

 lies one of the dangers of the method. A com- 

 mon type is not undesirable, indeed it is often 

 highly desirable. But it is only desirable when 

 it is a superior type and the cattle are elevated 

 to it. Great improvement has only been at- 

 tained by the adoption by some skillful breeder 

 of some high ideal type and the use of every 

 means in man's power to raise the stock bred 

 to that type. We have seen that changed con- 

 ditions of life, especially excessive increase of 

 nutrition, sometimes inbreeding, as in the case 

 of the Longhorn bull Shakespeare, would pro- 



