PREFACE 



DURING the fourteen months preceding the date 

 on which this volume is issued I have devoted all 

 available time to work connected with the three 

 inspiring anniversaries of July 1, 1908, Feb. 12, 

 1909, and Nov. 24, 1909. With all diffidence I 

 have chosen the date which closes this period of 

 work, as the day of publication. It may help in 

 some small degree to keep in remembrance the 

 birthday of a mighty epoch in the history of 

 thought. 



The first Section of this book attempts to give 

 a brief account of the history which led up to and 

 followed the publication of the theory of Natural 

 Selection and the Origin of Species. Darwin's 

 sure scientific insight, and his views on evolution 

 by mutation, briefly treated in this Section, 

 receive further consideration in Appendices A 

 and B. The confusion of thought threatened by 

 the unintentional but most unfortunate mis- 

 representation of de Vries's term, * fluctuating 

 variability,' is pointed out in a footnote and 

 further considered in Appendix D. I have given 

 at the end of this Appendix a very brief account 

 of certain phases of thought, during the past 



