THE PRINCIPLES OF BREEDING 33 



primary principles of successful breeding, to the very great 

 advantage of the race of animals in which he interests 

 himself. 



Now, the thoughtful man who has attentively followed 

 the arguments hitherto advanced will probably have 

 taken note of the very grave danger which lies in the 

 temptation to resort to consanguinity, or in-breeding, 

 a curse which has done more to ruin popular breeds 

 than any other form of injudicious mating. Undoubtedly 

 the temptation is a strong one; for it is, unfortunately, 

 the shortest possible cut towards the establishment of 

 a desired standard. 



On the principle that " Like begets like," it is clear 

 that the more closely the required family characteristics 

 are combined in sire and dam the more certainly may 

 we expect to perpetuate these same characteristics in 

 their offspring, by following the line of least resistance. 

 Therefore, to take a very extreme case, we might argue 

 that if a litter contained a particularly good dog and a 

 particularly good bitch of similar shapes, it would be 

 practically certain that by mating the litter brother 

 and sister we should be able to count upon fixing and 

 perpetuating the desired type. 



And so, indeed, we could. But the cost of producing 

 paragons by resorting to close in-breeding is terrible to 

 contemplate. It strikes a blow at the future of the breed, 

 and results in deterioration of all such important attri- 

 butes as constitution, size, bone, prolificacy, mental 



