236 THE BREEDING OF ANIMALS 



it not as reasonable and as certain that you can intensify 

 strength of constitution, heavy bone, or vigor, if you have 

 those traits well developed in the blood of the animals 

 you are in-breeding ? I think I have continued to improve 

 my herd, being now able to produce a larger percentage 

 of really superior animals than at any time in the past ..." 



Another noted breeder of Berkshires who attributes 

 the high quality of his animals to the practice of in-breed- 

 ing is A. J. Lovejoy of Illinois. 'He is quoted in Daven- 

 port's " Principles of Breeding " as follows : 



1 " We are believers in quite close, even in-breeding. 

 We find the greatest show animals are closely in-bred. 

 Sires to half-sisters is the most common form of close 

 breeding, though cousins, nephews, and nieces, and even 

 brothers and sisters are bred together with great success. 

 It of course requires good judgment in mating animals 

 that are particularly strong in individual merit. Should 

 each have a bad defect in any way, we should expect 

 that to be more manifest in the offspring than in the par- 

 ents, and likewise the good points would be better; so 

 if one mates equally good specimens the produce will be 

 an improvement. There is no sire of any breed so pre- 

 potent as an in-bred sire. When we get to the point 

 where we feel the need of outside blood we mate an im- 

 ported sow with our best boar, and from this litter we 

 select a boar to use on the get of his own sire from other 

 sows in the herd ; that is, we breed this boar on his own 

 half-sisters." 



219. In-breeding corn. Many of the principles which 

 are now universally accepted as guides to practice in 

 animal-breeding were first discovered by plant-breeders. 

 The mendelian principle is a good example of this fact. 



1 Davenport, "Principles of Breeding," p. 625. 



