34 ENGLISH MEN OF SCIENCE. [CHAP. 



birth of the scientific men, the ages of their 

 fathers average 36 years, and those of their 

 mothers 30. The details are shown in the table 

 below : 



Putting these facts together, viz. (1) that 

 elder SODS appear nearly twice as often as younger 

 sons ; (2) that, as regards intermediate children, 

 the elder and younger halves of the family contri- 

 bute equally ; and (3) that only sons are as common 

 as eldest sons, we must conclude that the age 

 of the parents, within the limits \vith which we 

 chiefly have to deal, has little influence on the 

 nature of the child ; secondly, that the elder sons 

 have, on the whole, decided advantages of nur- 

 ture over the younger sons. They are more 

 likely to become possessed of independent means, 

 and therefore able to follow the pursuits that 

 have most attraction to their tastes ; they are 



