200 THE CONTROL OF LIFE 



sional classes in Britain ? The question is whether 

 there is a constitutional decrease of fecundity, or whether 

 what is observed is in the main an indirect result. For 

 it is probable that a reduction of fertihty among the 

 highly individuated may be in part due to the frequency 

 of marriages that are not love-marriages, to the fre- 

 quency of late marriages, to selfish or timid non-mater- 

 nity, to dehberate evasion of parentage, and even to 

 overstrain in early efforts after self-realisation. It is 

 also to be remembered that, up to a certain point, im- 

 proved conditions of life tend to lessen multiplication 

 indirectly, for new interests divert the animal nature 

 and better housing lessens the provocations to sen- 

 suality. 



While there is no doubt as to the occurrence of types 

 constitutionally sterile, or relatively infertile, or with 

 strongly inhibited sex impulses, little is known as to 

 their relative frequency ; and apparent infertility among 

 the highly individuated can be in great part accounted 

 for as an indirect result. There is very little evidence 

 that heightened individuation brings about lessened 

 reproductivity as a physiological consequence in the 

 individual. 



§ 4. Rise and Fall in Population 



Even in ancient times fluctuations of population 

 were well known. Over and over again the following 

 sequence occurred. In a limited area the increasing 

 population began to overtake the means of subsistence. 

 To reUeve the pressure recourse was had to all sorts 



