804 STUDIES, SCIENTIFIC AND SOCIAL chap xiv 



are not necessarily the same as those which have produced 

 the separate orders, classes, and sub-Jdngdoms from more 

 remote common ancestors. That all have been alike 

 produced by " descent with modification " from a few 

 primitive types, the whole body of evidence clearly 

 indicates; but while individual variation with natural 

 selection is proved to be adequate for the production 

 of the former, we have no proof and hardly any good 

 evidence that it is adequate to initiate those important 

 divergences of type which characterise the latter.^ 



^ Since this chapter was written the argument has been strengthened 

 l)y numerous additional observations of variation by other naturalists, 

 many hundreds of individuals of a species being measured ; and in 

 every case variation to a large amount has been found to exist in every 

 part or organ thus tested. 



