XV 



THE VALUE OF COLOUR IN THE STRUGGLE 



FOR LIFE 



By E. B. Poulton. 



Hope Professor of Zoology in the University of Oxford. 



Introduction. 



The follo^ving pages have been Avritten almost entirely from 

 the historical stand-point. 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 sug- 

 gested 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 contribution 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 Protective Resemblance, Warning Colours, and Mimicry both 

 Batesian and Miillerian. It would have been superfluous to explain 

 these on the present occasion ; for a far more detailed account than 

 could have been attempted in these pages has recently appeared ^ 

 Among the older records I have made a point of bringing together 

 the principal observations scattered through the note-books and 

 collections of W. J. Burchell. These have never hitherto found 

 a place in any memoir dealing with the significance of the colours of 

 animals. 



Incidental Colotirs. 



Darwin fully recognised that the colours of living beings are not 

 necessarily of value as colours, but that they may be an incidental 

 result of chemical or physical structure. Thus he wrote to T. Median, 

 Oct. 9, 1B74 : "I am glad that you are attending to the colours of 



1 Poulton, Essays on Evolution, Oxford, 1908, pp. 293—382. 



