736 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Blood Relationship in Marriage. 



A raGinoir with this title, by Dr. Mitchell, is included in a recent 

 publication by the London Autropological Society. The author 

 confined his investigations to Scotland, where his duties as Deputy 

 Commissioner of Lunacy have led him to examine many cases of 

 insanit}^ and defective development, some of which he attributes 

 to the influence of consanguinity. His conclusions are as follows : 



L That consanguinity in parentage tends to injure the offspring. 

 This injury assumes various forms, as diminished viability, feeble 

 constitutions, bodily defects, impairment of the senses, disturbance 

 of the nervous system, and sterility. 



II. That the injury may show itself in the grandchildren, so 

 that there ma}- be given to the offspring by the kinship of the 

 parents a potential defect, which may become actual in the children, 

 and thenceforth, perhaps, appear as an hereditary disease. 



III. That idiocy and imbecility are more common than insanity 

 in such cases. 



We may add here that the first thorough investigation on this 

 subject was made in the State of Massachusetts, nearly twenty 

 years ago, by commissioners appointed "to inquire into the con- 

 dition of the idiots of the commonwealth, to ascertain their num- 

 ber, and whether anything can be done in their behalf." Under 

 them 63 towns were examined, and 361 idiots were found. Dr. 

 S. G. Howe, in his able report to the Senate of that State, described 

 many sad cases which were the direct result of misconduct on the 

 part of one or both parents. On the effect of intermarriage of 

 relatives, he said : 



"In assigning this as one of the remote causes of idiocy, it is 

 not meant that, even in a majority of cases, the offspring of mar- 

 riao;e between cousins, or other near relations, will be idiotic. 

 The cases are very nr.merous where nothing extraordinary is 

 observable in the immediate offspring of such unions. On the 

 other hand, there are so many cases where blindness, deafness, 

 insanity, idiocy, or some peculiar bodily or mental deficiency, is 

 seen in such offspring, of the first or second generation, that one 

 is forced to believe -they cannot be fortuitous. Indeed, the infe- 

 rence seems irresistible that such intermarriages are violations of 

 the natural law, though not such flagrant ones as always to be fol- 

 lowed by obvious and severe punishment. 



" Out of 359 cases in which the parentage was ascertained, one- 

 twentieth of the whole were the offspring of the marriage of rela- 



