16 PRINCIPLES OF BREEDING 



a commercial animal. Warfield describes the results in a 

 sentence which is curiously descriptive of the position 

 attained by Bates with his unrivalled Duchesses : 



" A few men for fancy and fashion's sake may prefer to 

 breed animals uncertain and irregular as breeders, short- 

 lived and delicate in constitution, producing many dead-born 

 and sickly calves, for the sake of now and again one of 

 extraordinary excellence which, perchance, may never produce 

 a calf to perpetuate her own phenomenal excellence." 



Line-breeding is a modified modern form of in- 

 breeding which is steadily becoming more popular as the 

 evil results of close-breeding become better understood. 

 Animals belonging to the same " line " of descent are bred 

 together, but close relationships are strictly avoided. By 

 this means constitutional vigour is maintained, and uniformity 

 of type given to the progeny. The advantages of in-and- 

 in breeding are secured without the ultimate correlated dis- 

 advantages, but the rate at which a desired type can be 

 reached by line-breeding is slower than that of in-and-in 

 breeding. Only the impatient and the inexperienced are 

 now found to follow the more dangerous headlong course. 



Natural breeding is one of several human methods of 

 attempting to rise above the natural average in one or more 

 directions. The law of the survival of the fittest is that 

 which has produced Nature's average or dead-level. The 

 struggle for life, which is the great guarantee of constitution, 

 being eliminated, natural breeding is resolved into the 

 selection of the fittest or best animals to breed from for a 

 given object, the attainment of which would be to rise above 

 Nature's average. The keynote of the system is individual 

 merit, not necessarily restricted to pedigree or any other 

 artificial, imaginary, or ideal standard. It is the method 

 adopted in the breeding of the American trotting horse, where 

 the quality of " performance " alone ranks in determining 

 merit. It is also applied with marked success in the breed- 

 ing of the milch cattle of Australia, where only heifers from 

 the best milking cows, tested for quality and quantity of 

 milk, are reared for breeding, and where all inferior milking 

 animals are spayed, so that, while they may continue to milk 

 for a year or two, they can no longer produce inferior offspring. 

 Out-crossing becomes the safe rule by which constitution is 



