The Age of Parents 47 



of births in the pedigrees furnished the material 

 to be measured by normal distribution as a 

 standard. The results are given in the follow- 

 ing table: 



Percentages of Births to Fathers of Different Ages. 



In Pedigrees Relative 



Age of In Normal of Emi- Value of 



Fathers Pedigrees nent Men Father Age 



24 and under 9.06 1.63 1.000 



25 to 29 23.05 9.77 2.3S6 



30 to 34 26.00 16.63 3.SS7 



35 to 39 19.67 19.19 5.426 



40 to 44 13.39 20.23 8.406 



45 to 49 5.50 14.53 14.670 



50 to 54 2.22 10.12 25.328 



55 to 59 0.72 4.30 33.138 



60 and over. 0.39 3.60 51.562 



100.00 100.00 



This table shows that normally more than 9 

 per cent of all children are bom when their 

 fathers are less than 25 years of age, but that 

 in the pedigrees of eminent men less than 2 per 

 cent are the offspring of such young fathers. 

 Normally more than 23 per cent of children are 

 born after the fathers are 25 and before they are 

 30, but in pedigrees of eminent men less than 

 10 per cent are the offspring of such young 

 fathers. Continuing the comparison, it is seen 



