CHAPTER IX. 



IN-AND-IN BREEDING. 



THE term in-and-in breeding is generally used to 

 indicate the breeding together of animals that are 

 closely related. 



As to the degree of relationship, in the breeding 

 of animals, to which this term should be applied, it 

 not only appears that no definite rule has been estab- 

 lished, but that almost every writer uses it with a dif- 

 ferent shade of meaning. 



The prevailing differences of opinion in regard to 

 the effects of in-and-in breeding have, to some extent 

 at least, arisen from this diversity of meaning in the 

 use of the term, and a misapprehension as to the real 

 advantages that are aimed at in its practice. 1 



1 In-and-in breeding has been denned as follows : " The breeding 

 from close affinities " Youatt on " Cattle," p. 525. " The breeding 

 from close relations" Johnson's "Farmers' Cyclopaedia," p. 248. 

 " Breeding between relatives without reference to the degree of con- 

 sanguinity" Randall's "Practical Shepherd," p. 116. "It should 

 only be applied to animals of precisely the same blood as own brother 

 and sister " Bowly, Journal of the Royal Agricultural Society, vol. 

 xix., p. 149. " Breeding from the same family, or putting animals of 

 the nearest relationship together " Sinclair's " Code of Agriculture," 

 p. 93. " The pairing of relations within the degree of second cousins, 

 twice or more in succession " Stonehenge on " The Horse," p. 140. 



