42 l'IlOC£EDINGS OF THE 



unprepared for tlie astonishing ])olyinorpliic mimicry ot" both 

 sexes in the African forms of Jlt/poliouias proved by Millar, in 

 the still more wonderful forms of the African Pseuducnea eari/tas 

 j)ro\ed by Jordan and confirmed by breeding by Carpenter, and in 

 tlie S. American lleliconiiie forms mentioned in the Appendix 

 (p. 51) and |)roved to be conspecific by Elrringham. In all of 

 these the transitional relationship between tlie patterns in each 

 set of polymorphic forms can be traced and the conclusions based 

 ou pattern brought into line with those based on structure and on 

 breeding. No such relationship exists (except in some of the 

 JfeHcijnuuv) between the patterns of any of the different species 

 which contribute the set- of models for each group of polymorphic 

 mimics, and the whole series of facts strongly opposes Pro- 

 fessor Punnett's liypothesis of the mutational origin of mimicry 

 from a set of factors identical with those which produce the 

 pattern of the model. 



I propose now briefly to consider the best known and most 

 striking of the much rarer cases in which the models as well 

 as their mimics are polymorphic ; for here if anywhere in pol}^- 

 morphic mimicry we sliould expect to find evidence in favour of 

 Professor Punnett's hypothesis. I refer to Dannida chi-i/!,i/iin(s 

 with its three forms chrijsipjpus, alcippus, and dorijipas, all of 

 wliich are well known to be mimicked in Africa by the female 

 of Ili/poHmnas misippus, and by both sexes of Afiwa encedon, 

 while tile first and last are mimicked by two forms of a Mimacnpa 

 (Lyccenidte) probably belonging to the same species. Here then 

 are three forms of a model mimicked respectively by three forms 

 of the female of one mimic and both sexes of another. It might 

 be expected that the latter at any rate, for the model also is 

 polymorphic in both sexes, would present the essential similarity 

 due to the appearance in both of the same. pattern factors. But 

 as I pointed out in 1902 * the different forms of chrysippus are 

 far more sharply separated from one another than those of its 

 mimics. All three of the latter show a much wider range of 

 ])attern variation and especially of transition between their 

 polymorphic forms. And this is conspicuously evident in Acra'a 

 encedon with both sexes polymorphic. Accompanying these 

 characteristics of the mimetic pattern tliere is the usual dyslegnia, 

 while the model is eulegnic except in the feature described ou 

 p. 38, Note *. 



a. Polijiiwiphic Fo7-ms, ■ — JSlhnctlc Constant and Non-Mimetic 

 YarUthle, — in the Same Species. — In another respect recent dis- 

 coveries in the ])olymorphic mimics throw light upon the origin 

 and growth of mimicry, strongly supporting the Darwinian 

 inter|)retation. Thus Dr. Carpenter has shown f tliat in certain 

 islands in the N.W. of the Victoria Nyanza where for some reason 

 the mimics are much commoner than their models, intermediates 



* 7ra7is. Kilt. Sec. Lovcl., Ip(t2. pp. 483. -184. 

 t Trans. Knt. Soc. Loud., 1014, pp. G06-645. 



