MULTIPLICATION OF THE HUMAN RACK. 49ii 



And certain seemingly -ad verse facts, prove, on examination, 

 to be facts belonging to a different category from that in 

 which they are placed, and harmonize with the rest when 

 rightly interpreted. 



The conformity of human fertility to the laws of multipli- 

 cation in general, being granted, it remains to inquire what 

 effects must be caused by permanent changes in men's natures 

 and circumstances. Thus far we have observed how, by their 

 extremely-high evolution and extremely-low fertility, man- 

 kind display the inverse variation between Individ uation and 

 Genesis, in one of its extremes. And we have also observed 

 how mankind, like other kinds, are functionally changed in 

 their rates of multiplication by changes of conditions. But 

 we have not observed how alteration of structure in Man 

 entails alteration of fertility. The influence of this factor is 

 so entangled with the influences of other factors which are 

 for the present more important, that we cannot recognize it. 

 Here, if we proceed at all, we munt proceed deductively. 



