l6o THE NATURE-STUDY REVIEW [i, 4, july 1905 



found animals closely resembling their immediate environment 

 in color and thereby more or less concealed from our human eyes ; 

 and we have concluded that the purpose of the color harmony is 

 protection from enemies. Other animals, carnivorous ones, seem 

 to be hidden from approaching prey. Still others display colors 

 contrasting strongly with the environment and the conspicuous- 

 ness has been taken to mean warning colors or danger signals 

 associated with qualities unpleasant to enemies. And more inter- 

 esting than all these, similarity between two animals {e. g., two 

 butterflies) has been given the interpretation that one is protected 

 from enemies by its warning colors backed up by disagreeable 

 qualities which enemies have learned to avoid, and the other is a 

 helpless impostor who by virtue of his resemblance lives on the 

 notoriety of the one whose conspicuous colors are danger signals. 

 Thus the Darwinian suggestions have given us most interesting 

 interpretations, and we have felt confident that we had the reasons 

 why most animals are colored as they are. 



And now come the doubting critics and serious questions are 

 raised. For many years biological literature has contained doubts 

 concerning the wide application of the theories of color interpre- 

 tation as advocated by Darwin and Wallace. Observations in 

 nature have in many cases failed to prove that the life of animals 

 always depends upon colors as the theory demands. Because a 

 harmonious blending of colors is practically concealment from our 

 human eyes does not prove anything so far as animals are con- 

 cerned. We must know from critical study just how far color 

 relations mean anything in connection with habits of animals ; and 

 many biologists have doubted the all-sufficiency of the explana- 

 tion offered by the color theories, because in very many cases 

 color and habits of life of certain animals are antagonistic so far 

 as the protective theory is concerned. 



In a popular article, " Gay Plumes and Dull," in Atlantic 

 Monthly for June, 1905, John Burroughs expresses his own doubts 

 concerning the wide application of the color theories, and many 

 of his views are quite in line with criticisms pointed out by biolo- 

 gists within recent years. 



First, Mr. Burroughs points out that " nature plays fast and 

 loose " with colors. One animal has concealing colors and 

 another similar one, often of the same family and even the oppo- 

 site sex, is conspicuous by its brilliance. " If dull colors are pro- 



