vi PREFACE 



to myself, and also much more extensive in some 

 lines. My desire has been more specially to show what 

 should be done, in future, on behalf of the Evolution 

 Theory, so that I may be excused if I have not gone 

 entirely through the facts of the past ; and as I consider 

 that experiment is now the only method of secur- 

 ing any further advance in solving the problems of 

 organic evolution, I have wished to state the matter 

 clearly, and to give some circulation to the statement 

 in the country where this line of study has most 

 followers. 



And now I should ask of my readers to excuse such 

 literary or grammatical defects as they may meet with 

 in this volume. A foreigner can scarcely be expected 

 to master all the niceties of the English language. 

 However, my friends Prof. Patrick Geddes and J. A. 

 Thomson having been kind enough to look over the 

 proofs and this I most sincerely thank them for 

 I feel the most important inelegancies or errors have 

 been excluded, although English readers must doubt- 

 less perceive that the author is not writing in his 

 native language. 



H. DE V. 



MONTMORENCY (SEINE ET OISE), FRANCE, 

 October io//z, 1891. 



