BREEDING IN-AND-IN. 101 



To introduce new blood, however good in other respects, is 

 to diminish the fixity of character. To breed in close affinities 

 from these selected specimens is to intensify it. The advantages 

 of such a system of breeding are patent to all, but the question 

 arises, whether it has not also its serious drawbacks if followed 

 too far ? And I fear the answer must be that it has. I have 

 known certain strains of Cotswold sheep and Durham cattle in 

 which extreme excellence had been attained by close breeding, 

 but only at the expense of a troublesome taint of consumption, 

 and many of us can recall instances of deafness and web fingers 

 or toes among the children of marriages between first cousins. 

 Mr. Druce, a successful breeder of Oxford pigs, says : " Without 

 a change of boars of a different tribe but of the same breed, con- 

 stitution cahnot be preserved." With the enfeebled constitution 

 which results from persistent breeding from father and daughter, 

 brother and sister, uncle and niece, there is also a concentration 

 of whatever constitutional taint of disease may reside in the 

 family. Lafosse mentions a breed of small black horses kept by 

 a farmer in L'Aisne, and bred in and in. They were subject to 

 specific ophthalmia, and soon the morbid taint became so con- 

 centrated that the whole family, with scarcely a single exception, 

 was blind. 



The doctrine that close breeding tends to sterility is supported 

 among others by Sebright, Knight, Lucas, Nathusius, Youatt, 

 Bates, Darwin, Magne, ^Macknight, Madden, Spooner, W^ood and 

 Carr. The wild white cattle of Chillingham Park, Northumber- 

 land, which have had no cross since the 12th century, " are bad 

 breeders," the annual increase being but one to five. The 

 equally ancient race in the Duke of Hamilton's park produce 

 but one to six. Shorthorn cows, proving barren when put to a 

 near relation, are often fertile with a bull of another breed, or 

 even of a distant strain of their own. 



Among sheep, Jonas Webb found it needful to maintain five 

 separate families on his farm that he might introduce fresher 

 blood of the same family into each at certain intervals. 



But pigs have, above all, shown sterility from close breeding. 

 Mr. Fisher Hobbes found it necessary to keep three separate 

 families to maintain the constitution and fruitfulness of his im- 

 proved Essex breed. Lord Western bred from an imported 

 Neapolitan boar and sow until the family threatened to become 



