EVIDENCES OF EVOLUTION. 87 
have descended or have been evolved from simpler ancestors, 
and these from still simpler, and so on, back to the mist of 
life’s beginnings. None of the evidence is logically demon- 
strative; 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 
modification 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). 
