:>56 



THE PLACE OE :\IIMICRY 



species, leading' it to resemble two or more models, 

 althoiiL^di at first sii^dit suL^i^estino^ only a Batesian inter- 

 pretation, does not by any means exclude the Miillerian. 

 The facts presented hy a dominant \vell-|)rotected 

 Acraeine mimic prove that a resemblance to more than 

 one model cannot serve as a criterion between the two 

 rival theories. 



14. y/ /\)ssid/c I)ista)icc oj Observable CJiaiio^c in 

 a Me?nber of a MiilUyian Group since 1825-7. — A |)o\ver- 

 ful combination ^ of distasteful butterflies in Eastern 

 Brazil has developed a characteristic pattern of which the 

 most marked feature is a bright yellow horizontal band 

 runniuij" alon<i^ the hind winn^. The central members are 

 ItJiomiijiac and IIcIiconi}iac. An outlying member is the 

 Danaine butterfly Lycorca halia, with a pale band instead 

 of a briL^ht \ellow one. In the Hope Collection at Oxford 

 there are eight examples, captured by \V. J, Burchell, 

 in Brazil, between Nov. 10, 1825, and Dec. 24, 1827. 

 There can be no doubt that these specimens, which are 

 in very good condition, are on the whole further removed 

 from the combination than captures of recent date, ' inas- 

 much as the band is but slightly paler than the tawny 

 ground colour of the wing.' Unless, therefore, there has 

 been a darkening of tint with age, we have here an example 

 of ai)proach towards the combination since 1825-7. The 

 case is j)recisely of the kind in which some observable 

 change might be looked for. That a buttertly which is 

 outlying to-day should have been even more outlying 

 seventy-five )'ears ago, is not surprising. But many 

 further observations must be made before the evidence 

 can be accepted as in an\' way satisfactory.^ 



B. AixArosLMATic Colours, or Adventitious 



Warning Colours. 



Certain j)alatable animals make use of the Special 

 r3efence and Warnincr Colours of other forms. Thus, 

 the common b^ni'lish hermit-crab, Pao^uriis berjihardus^. 



' Blandford's Series iv, Group 3, Division ((7): see Proc. Ent. Soc, 

 Lottd., 1897, p. xxiv. 



' See Ann. Mag. Nat. Hist., ser. 7, vol. xiii, May 1904, pp. 359-60. 



