THE VALUE OF COLOUR IN THE 

 STRUGGLE FOR LIFE 



Essay XV in Darwin and Modern Science : Essays in com- 

 memoration of tlie centenary of the birth of Charles Darwin and 

 of the fiftieth anniversary of the publication of l The Origin of 

 Species ', edited by Prof. A. C. Seward, Cambridge University 

 Press (1909), 271-297. Somewhat extended. 



INTRODUCTION. 



THE following pages have been written chiefly 

 from the historical standpoint. Their principal 

 object has been to give some account of the 

 impressions produced on the mind of Darwin 

 and his great compeer Wallace by various difficult 

 problems suggested by the colours of living nature. 

 In order to render the brief summary of Darwin's 

 thoughts and opinions on the subject in any way 

 complete, it was found necessary to say again 

 much that has often been said before. No attempt 

 has been made to display as a whole the vast con- 

 tribution of Wallace ; but certain of its features 

 are incidentally revealed in passages quoted from 

 Darwin's letters. It is assumed that the reader 

 is familiar with the well-known theories of Pro- 

 tective Resemblance, Warning Colours, and Mimi- 

 cry both Batesian and Mullerian. It would have 



