EMINENT FAMILIES. 193 



stances in which their system fails to operate, where are we to look 

 for the advantages of early reproduction? Perhaps we may look 

 for it in the compensation that gives the material advantages to that 

 member of the family least able to contend with the adversities of 

 life. The trouble with primogeniture is, however, that the compen- 

 sation is disproportionate to the mental differences. In any given 

 family that does not extend from very early to very late reproduc- 

 tion, there is usually very little, and often no recognizable, differ- 

 ence between the eldest and the youngest. Except in cases of 

 extreme difference it is only through successive generations that 

 great results are reached. A single case of comparatively early 

 reproduction does not eliminate the accumulation of several genera- 

 tions on both sides of the house, as we see in Alexander, Moham- 

 med, Swift, Lincoln and Gray. Neither is a very great man 

 produced in a single generation, but it requires two or three genera- 

 tions and more than a century of time. 



