PBEFACE. 







THE present volume bas grown out of materials which I 

 had collected for the " Davis Lectures," delivered by me 

 in the Zoological Society's Gardens during the spring of 

 1890. This Look is addressed, as were the lectures, to persons 

 having no special knowledge of zoology, but that general 

 interest in the facts and problems of the science, which is now 

 so widely spread. It contains hardly anything novel, but 

 professes to give some account of the principal phenomena 

 of coloration exhibited by animals. Some of the facts and 

 theories, however, have not, so far as I am aware, as yet 

 found their way into works of a popular character ; I refer 

 particularly to the ingenious theories of Dr. Eisig and 

 M. Stolzinaim. Inasmuch as Mr. Poulton's work upon the 

 Colours of Animals, recently published as one of the volumes 

 of the " International Scientific Series," and Mr. Wallace's 

 sketch of coloration in his " Darwinism," deal with colour 

 ;il most entirely from the point of view of natural selection, 

 1 have attempted to lay some stress upon other aspects of 

 the question. The literature relating to animal coloration is 

 enormous ; so much so that it is really beyond the powers of 

 any person who cannot give up his whole time to abstract 

 it thoroughly. To write an exhaustive work upon Animal 

 Coloration requires a sort of naturalist that now hardly can 

 exist a specialist in every group. However, all that I have 



