A STUDY OF BRITISH GENIUS. 60 1 



are the youngest members of large families. Bohannon found that 

 youngest children tend to be exceptional and abnormal, precocity being a 

 specially prominent trait among them. Among the socially degenerate 

 classes Dugdale found first-born and last-born prominent, the former 

 tending to be criminals, the latter paupers. 



Whenever it has been possible I have noted the age of the father 

 at the birth of his eminent child. It has been possible to ascertain 

 this in 204 cases, and the data thus obtained may be considered as fairly 

 free from fallacy, so far as the biographical mind is concerned. The 

 range of age is considerable, from 15, the age of Napier of Merchiston's 

 father at his birth, to 79, the age of Charles Leslie's father, the period 

 of potency in the case of the fathers of persons of eminent ability thus 

 ranging over 64 years. The 204 cases may be grouped in five-year 

 age-periods as follows: 



Under 20 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60 and over 

 1 7 22 54 41 33 24 9 7 6 



These figures run in a fairly smooth and regular way, and I believe 

 that they are very noteworthy and significant. It will be seen that 

 30-34 is the most frequent age of fatherhood, and that while there are 

 very few cases of fatherhood during the ten preceding years, when 

 sexual vigor is at its height, the majority of eminent persons have been 

 begotten by fathers who had already passed this age of most frequent 

 fatherhood. This result is the more significant when we remember 

 that we are chiefly dealing with the upper social classes (for it is in their 

 cases that these facts are most easily ascertained), and that we must 

 exclude the quite modern tendency to retardation of the age of mar- 

 riage. I have no figures of the age of fatherhood among normal sub- 

 jects quite fairly comparable with those here presented. The signifi- 

 cance of the age of fatherhood has been chiefly studied, so far as I am 

 aware, by Marro in North Italy, and we cannot assume that the condi- 

 tions are there quite the same. Marro divided the fathers of his normal 

 subjects into three classes: (1) Below 25 years of age, a stage of imma- 

 turity; (2) from 26 to 40 years of age, a stage of maturity; (3) over 40 

 years of age, a stage of decadence. He found that 8.8 per cent, fathers 

 of normal subjects belonged to the first group, 66.1 to the second class 

 and 24 to the third. The corresponding figures for the fathers of the 

 persons of eminent ability concerned in the present inquiry are 3.9, 57.3 

 and 38.7. Whatever the value of this comparison, there can be little 

 doubt that an abnormally high age prevails among the fathers of our 

 eminent persons. I have only been able to ascertain the age of the 

 mother in 40 instances. In these cases it is distributed as follows: 



Age of mother 21-24 25-29 30-34 35-39 40-44 45-49 50 



Number of cases 8 13 8 5 4 1 1 



Except for the one very unusual instance at 50 (Dibdin's mother), 



