IN-AND-IN BREEDING. 185 



I 



not an essential result of marriage of consanguinity 

 that there should be scrofulous or other degeneracy." 

 Dr. Edward Jarvis, the distinguished statistician, in a 

 letter to Dr. Newman, says : " Cousins, descendants 

 from a common ancestry, have a common heritage 

 of good, of evil, of power, and weakness ; and, if these 

 join in marriage, their issue have a double chance of 

 inheriting whatever qualities they may both possess. 

 If, then, both parents, although cousins, are perfect in 

 constitution and health, and have nothing to transmit 

 but power, then their children have a double security 

 against constitutional imperfection, and a double war- 

 rantee of inherited capacity and strength. The con- 

 verse is also true with cousins who have imperfections 

 and liabilities in common. If they marry, they pro- 

 vide a double chance of the repetition of the same 

 weaknesses and susceptibilities in their offspring. . . . 

 In this view of the matter, the objection to consan- 

 guineous marriages lies not in the bare fact of their 

 relationship, but in the fear of their having similar 

 vitiations of constitution." 



Dr. Newman gives the details of thirty-two in- 

 stances of consanguineous marriages, in different locali- 

 ties. The result, as far as reported, was one hundred 

 and twenty-seven children, or nearly an average of four 

 to each marriage, and there were instances of eight, 

 eleven, twelve, and even fourteen children in a family ; 

 while but one marriage proved unproductive, but in 

 this case both parties were affected with disease. Of 

 the one hundred and twenty-seven children, but four- 

 teen died under two years of age, which is eleven per 

 cent. ; while iix Michigan, in 1870, according to the re- 



