240 rHEORlKS OF MIMICRY 



white a|)[)earance. This fact holds true even for such 

 a speciaH/ed and perfect mimic as DisDio) pJiiiia arise. 



F. D. Godman, b\R.S., and O. SaKin, 1\R.S.,^ speak of 

 these hidden chalk)- patches, surrounded by a silky area 

 covered bypeculiarscales.asacharacterof theDismorphina. 

 The interpretation of the patch as a sexual brand, perhaps 

 with the nature of a scent-producinc^ organ, does not in 

 any wa)' disprove the suggestion here adopted — that the 

 white pigment in the scales is a survival from an ancestral 

 condition still found over the greater part of the wing- 

 surface in so man)- non-mimetic Picrinae, as well as in the 

 males of many mimetic species (e.g. in the genus Mylo- 

 //wis). It should be noted, however, that the patch is not 

 white in all species of the Dis7)iorphina. Mr. Belt - states 

 that the white patch is usually concealed by the males, 

 as indeed may be inferred from the change in character 

 of the surface, which indicates the normal amount of 

 overlap of the fore upon the hind wing. The same 

 author, l)elieving that the white [jatch is ancestral and 

 has been retained by the operation of Sexual Selection, 

 makes the daring suggestion that it may be * an attraction 

 in courtship, to exhibit to the females, and thus gratify 

 a deep-seated preference for the normal colour of the 

 order to which the Leptalides [Dismorphina] belong'. 



The rigid restriction of mimetic effects to those parts 

 of the surface which can be seen tells very strongly 

 against any theory which is not based on the principle 

 of Selection. 



7. Ils^ential Xixture of these Resemblances : //ui'r A nalysis 

 info the several kinds of Effect produced. 



The resemblances under discussion are made up of 

 elements of very different kinds conibined in single 

 individuals; but the essentially composite nature of the 

 effect easily yields to analysis. Some of these complex 

 combinations only require to be stated in order to show 

 the inadequacy of the theory which is most usually 



' In the Biologia Caitrali- Americana (Rhopalocera, vol. ii, p. 173). 

 ' Naturalist in Nicaragua, 2nd ed., London, 1888, pp. 384. 385. 



