282 PROCEEDINGS OF THE ACADEMY OF [June, 



also proposed to explain cryptic resemblances, or the mimicry of 

 inanimate objects by natural selection. Four years later, A. R. 

 Wallace stated' 2 that he agreed entirely with Bates as to the cause of 

 mimicry, and cited many examples of the phenomenon from the 

 Malayan region. In 1867 the same author first gave a definite 

 theory 3 concerning the significance of the brilliant colors which are 

 now commonly referred to as warning colors. In 1870 4 he extended 

 the application of Bates' theory of cryptic and mimicking colors 

 and advanced the results of experiments in support of the theory of 

 warning colors. 



It is not necessary at this time to trace the later development of 

 the theory by Miiller, Dixey, Poulton, and others. Suffice it to say 

 that the original definite suggestion that conspicuous colors have 

 been developed to advertise disagreeable qualities was the result 

 of Wallace's cudgelling his brain at Darwin's instance, for an explana- 

 tion of the coloration of certain insect larva?, which obviously could 

 not be accounted for by sexual selection. The theory has since been 

 expanded to include conspicuous coloration in all groups of animals. 

 A certain insect smells badly to man ; is colored red and black, for 

 example, it is conspicuous and nasty to us, hence it must be to 

 insectivorous animals. Its striking color advertises its nauseous 

 qualities and it is avoided after experience; in other words, is pro- 

 tected. So goes the original theory. Although it has been expanded 

 to include all conspicuous forms, whether or not they are nauseous 

 to man, its supporters seemingly find it impossible entirely to forsake 

 the older anthropomorphic ground. Mimicry theories hold that a 

 palatable form gains protection by resembling one of the conspicuous 

 but nauseous ones, and that distasteful forms are mutually benefited 

 by resemblance. Each of these theories, it may be repeated, was 

 built up in the absence of evidence that the insects concerned were 

 actually distasteful or palatable as claimed. This was the principal 

 criticism made by the comparatively few who at the time dared 

 question the all-sufficiency of natural selection, and it stands to-day 

 the greatest obstacle to acceptance of the theories. 



This criticism spurred the supporters of the theory to sporadic 

 efforts to produce evidence in favor of their contentions. The 

 favorite method of securing such evidence has been by experimenting 

 with captive animals, and the principal body of alleged proof of the 



2 Trans. Linn. Soc. Lond., XXV, 1866, pp. 19-22. 



3 Proc. Ent. Soc. Lond., 1867, p. lxxxi. 



4 Contributions to the Theory of Natural Selection, 1870, Chap. III. 



