94 PRINCIPLES OF BREEDING. 



CHAPTER VII. 

 In-and-in Breeding. 



It has long been a disputed point whether the system 

 of breeding in-aruPin or the opposite one of frequent 

 crossing has the greater tendency to maintain or im- 

 prove the character of stock. The advocates of both 

 systems are earnest and confident of being in the right. 

 The truth probably is, as in some other similar disputes, 

 that both are right and both wrong — to a certain ex- 

 tent, or within certain limits. 



The term in-and-in is often very loosely used and is 

 variously understood ; some, and among these several 

 of the best writers, confine the phrase to the coupling 

 of those of exactly the same blood, i. e. brothers and 

 sisters ; while others include in it breeding from parents 

 and offspring, and others still employ the term to em- 

 brace those of more distant relationship. For the lat- 

 ter, the term breeding in, or close breeding, is deemed 

 more fitting. 



The prevalent opinion is decidedly against the prac- 

 tice of breeding from any near relationships ; it being 

 usually found that degeneracy follows, and often to a 



