SIGNIFICANCE OF SEXUAL REPRODUCTION, ETC. PREFACE. 253 



assume that the process of natural selection has had a far larger 

 share in the transformation of species than has been as yet 

 accorded to it ; for if such characters are not transmitted, the 

 modifying- influence of external circumstances in many cases re- 

 mains restricted to the individual, and cannot have any part in 

 producing transformation. We shall also be compelled to abandon 

 the ideas as to the origin of individual variability which have 

 been hitherto accepted, and shall be obliged to look for a new 

 source of this phenomenon, upon which the processes of selection 

 entirely depend. 



In the following pages I have attempted to suggest such a 

 source. 



A. W. 



FREIBURG i. BK., 



November 22, 1885. 



