From Savagery to Civilization 65 



of breeding. We got these improvements only 

 from parents, grandparents, great-grandparents, 

 etc., who developed their trotting muscles to an 

 unusual extent before reproducing. This fact is 

 seen partly from the individual histories of the 

 progenitors in those pedigrees, and partly from 

 the high ages at which they appear as sires and 

 dams. 



When we turn our attention to human beings 

 we find the same facts there. Intellectually emi- 

 nent men qome from old parentage and not from 

 young parentage. While an eminent man is 

 sometimes the son of comparatively young par- 

 ents, he is never the son of young parents who 

 were the children of young parents. In pedigrees 

 of eminent men the average age of one thousand 

 fathers, grandfathers, etc., was over forty years. 

 When we analyze the distribution of births in 

 the pedigrees of eminent men, and compare that 

 with the normal distribution, we find that the 

 older the father is when the son is born the 

 greater is the inherited mental ability of the son. 

 When we look back at the fathers and grand- 

 fathers of these eminent men to see what kind 

 of lives they lived before reproducing, we find 



