MIMICRY, MUTATION AND MENDELISM 



statement were correct, his explanation amounts to this — " It is so, 

 because it is so." But the statement is incorrect ; the patterns 

 only appear to be similar, and the problem to be solved is the pro- 

 duction of so striking a resemblance not out of the same, but out 

 of very different elements, — the fact that model and mimic are 



" Not like to like, but like in difference." 



We now come to a still more obvious objection. Darwinians, 

 according to Professor Punnett, believe that one Danaine model 

 arose directly although gradually, from the other — Mendelians, that 

 the origin was sudden. To suggest either the one or the other is to 

 show a want of acquaintance with the genus Amauris to which both 

 models belong. The two butterflies A. dominicanus and A. echeria 

 are widely separated. Aurivillius in his great " JRhopalocera 

 JEthiopica," places dominicanus (considering it to be a form of 

 niavius) as the second, echeria as the fifteenth species of Amauris, 

 and no systematist has suggested a nearer affinity. Dr. F. Moore, 

 in fact, in his revision of the Danaince* placed echeria and an allied 

 species in a separate genus, Nebroda. It would be interesting 

 to know whether Professor Punnett applies his hypothesis con- 

 sistently and believes that the Acraeine model of the planemoides 

 female of dardanus arose directly from one of the Danaine models 

 (or vice versd) ! 



In each of the examples of mimicry considered in the present 

 article we have to deal with distinct species of models resembled 

 not by distinct species of mimics, but by the polymorphic forms of 

 a single species. This is one of the most interesting aspects of the 

 question ; for, as Dr. Karl Jordan has argued, there are no grounds 

 for the belief that these polymorphic mimetic forms are on their way 

 towards the formation of separate species. Polymorphism itself 

 has become a character of the species, just as it has in the well- 

 known Kallimas with their various types of dead-leaf-like under 

 surface. It is, however, a character that is only kept up by constant 

 selection. We have seen in dardanus that the absence of the model 

 leads to the absence or the extreme rarity of the corresponding 

 female form. And the same is true of the Nymphaline mimic ; for 



* l'n>c. Zool. Soc, Lond., 1883, p. 201. 

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