260 



THE AMERICAN NATURALIST 



[Vol. LI 



to explain the existence of conspicuous creatures. The 

 sole concern of each was the interpretation of resem- 

 blances, which were later commonly considered mere in- 

 cidents in the attainment and use of warning colors. Thi.s 

 shifting of emphasis from "likeness which is perfectly 

 staggering""^ to conspicuousness, which failed to elicit a 

 single outspoken comment in the original papers of Bates 

 and Miiller, is distinctly chargeable to Wallace,* who ex- 

 tended his hypothesis of the functional conspicuousness of 

 bright colors, until it included the facts of mimicry. 



Abbott H. Thayer^ has proposed an explanation of the 

 resemblance between unrelated species of butterflies, 

 which is consistent with his thesis that the foremost func- 

 tion of animal coloration is concealment. This h}iDothesis 

 is Darwinian in principle, but in practise is directly op- 

 posed to current selectionist opinion. It is ])urely specu- 

 lative, and is stated as follows : 



Moi')' recently Thayer'" adds tlint in the paper from 

 wliich tlic excerpt aliovo is taken lie ascribed more im- 

 })ortance t.o butterflies' resemblance to flowers, as com- 

 pared to their rendering qi scenery, than he should at the 

 later date; but this necessitates no modification of his 

 idea that mimicry is mere incidental resemblance between 

 species, which, through selection based upon the obliter- 

 ative effect of their coloration, conform ever more closely 

 to one ideal representation of their common background. 



If the Darwinian ranks are divided upon the question 

 of the prex alence of conspicuous types of coloration, sim- 

 ilar tliouiili h'-- open (]issension appears among their op- 



