I08 THE DOCTRINE OF DESCENT 



have descended or have been evolved from simpler an- 

 cestors, and these from still simpler, and so on, back to the 

 mist of life's beginnings. None of the evidence is logically 

 demonstrative ; we accept the evolution idea because it is 

 a plausible interpretation which is applicable to many orders 

 of facts, and is contradicted by none. 



In accepting the evolutionist interpretation naturalists are 

 unanimous ; but in regard to the manner in which the 

 transformation of species or the general ascent of life has 

 been brought about, there is much difference of opinion. 

 The fact of evolution is admitted ; debate goes on with 

 regard to the factors (see Chapter XXVIII). 



