BREEDING TERRIERS 51 



takes advantage of the law of heredity to estab- 

 lish breeds. If like always exactly reproduced 

 like, however, that is as far as he could ever get, 

 but because there is infinite variation, the off- 

 spring differ from their parents. By selecting 

 those that come nearest his ideal, the breeder does 

 just the same as Dame Nature when she kills off 

 the unfit. 



Since earliest times, man, more or less without 

 thought or any knowledge of the whys and where- 

 fores, has been carrying on scientific breeding in 

 an unscientific way. Ever since he has kept do- 

 mestic animals, his selection, formerly more or 

 less unconscious, has been exerting its powerful 

 force. For generations, the dog fanciers have 

 been doing this : picking out the dogs and bitches 

 most to their liking and mating them. The re- 

 sult is that while all breeds of dogs are closely 

 enough related to inter-breed, still some are of 

 comparative age and most breed wonderfully 

 true to type. 



Until quite recently, the dog breeders have 

 been following the old, unscientific method, with 

 some additional effort to correct faulty points 

 in their dogs. That is, they have picked out in- 

 dividuals for breeding stock that came as near 

 as possible to their ideals, and if the prospective 

 mother was bad in head they selected a stud dog 



