38 ENGLISH MEN OF SCIENCE. [CHAP. 



namely, that a relative deficiency of health and 

 energy, in respect to that of their own parents, is 

 very common among them. Their absolute health 

 and energy may be high, far exceeding those of 

 people generally ; but I speak of a noticeable 

 falling off from the yet more robust condition of 

 the previous generation : it is this which appears 

 to be dangerous to the continuance of the race. 

 My figures give the remarkable result that there 

 are no children at all in one out of every three of 

 these cases. I think that ordinary observation 

 corroborates this conclusion, and that those of my 

 readers who happen to have mixed much in what 

 is called intellectual society will be able to recall 

 numerous instances of persons of both sexes, but 

 especially of women, possessed of high gifts of 

 every kind, including health and energy, but of 

 less solid vigour than their parents, and who have 

 no children. I do not overlook the fact that the 

 scientific men are an urban population, being 

 mindful of results I have published elsewhere 

 (Statistical Journal, 1873), which show a similar 

 diminution in the average fertility of townsmen 

 as compared with country folk ; but this would 



