WHAT IT MEANS 51 



that in one case, a defective man on the bad side of the 

 family was found in the employ of a family on the 

 normal side and, although they are of the same name, 

 neither suspects any relationship. 



We thus have a natural experiment of remarkable 

 value to the sociologist and the student of heredity. 

 That we are dealing with a problem of true heredity, 

 no one can doubt, for, although of the descendants of 

 Martin Kallikak Jr. many married into feeble-minded 

 families and thus brought in more bad blood, yet Mar- 

 tin Jr. himself married a normal woman, thus demon- 

 strating that the defect is transmitted through the 

 father, at least in this generation. Moreover, the 

 Kallikak family traits appear continually even down 

 to the present generation, and there are many qualities 

 that are alike in both the good and the bad families, 

 thus showing the strength and persistence of the an- 

 cestral stock. 



The reader will recall the famous story of the Jukes 

 family published by Richard L. Dugdale in 1877, a 

 startling array of criminals, paupers, and diseased per- 

 sons, more or less related to each other and extending 

 over seven generations. 



Dr. Winship has undertaken to compare this family 

 with the descendants of Jonathan Edwards, and from 



