I40 EVOLUTION OF BRITISH CATTLE 



to prevail ? In the face of some of the preceding 

 chapters and these considerations, in-breeding 

 must escape the charges against it with at least 

 the Scots verdict, not proven. When once a 

 breed has been established, however, that is to 

 say, when it has reached such a degree of steadi- 

 ness that it can be called " pure," the need for 

 in-breeding is greatly decreased. 



But what of the future ? Does the past offer 

 any guide ? Previous to the discovery of Mendel's 

 work, the dictum of the past as to the con- 

 ditions for success in cattle-breeding would have 

 been — 



(i) A good judge. 



(ii) Good stock. 



(iii) Line breeding with old-established and 

 in-breeding with new breeds. 



(iv) Ruthless elimination of the unfit. 



But although Mendelism would not alter the 

 dictum it would increase the breeder's power 

 by increasing his knowledge of the working of 

 Nature's laws. Already in this paper such of the 

 Mendelian knowledge as is yet known with 

 regard to cattle is referred to. So far that know- 

 ledge is not great, and it is largely concerned 

 with comparatively unimportant matters, like 

 colour, for instance ; but as the signs by which 

 Mendelian characters can be identified become 

 better known, it is hoped that information about 

 much more important matters than colour may 



