MIMICRY, MUTATION AND MENDEL1SM 



genus Hypolimnas is mimetic in one or both sexes, although this 

 is not true of dexithea, an extraordinary ancestral species of huge 

 size in Madagascar. The models are chiefly, in Africa almost 

 exclusively, Danaince. A group of African species, with both sexes 

 mimetic and both generally alike, is sometimes separated as a 

 distinct genus, Euralia, from Hypolimnas, in which the sexes are 

 generally unlike and mimicry is confined to the female ; but the 

 distinction breaks down on both sides. 



One of the commonest East African species of the group with both 

 sexes alike, Hypolimnas {Euralia) wahlbergi, resembles Amauris 

 dominicanus (Plate I., Fig. 2), while H. (E.) mima, a second species, 

 as it was regarded till quite recently, mimics the two species of 

 Amauris represented in Figs. 4 and 5 of the same plate. Just over 

 ten years ago Mr. Guy A. K. Marshall published his conviction 

 that wahlbergi and mima were a single species.* He pointed to the 

 facts that the two forms were known to pair, that intermediates 

 between them were known, and that he had observed them going 

 to rest together in the evening as the individuals of some species are 

 known to do. From that time I endeavoured to persuade African 

 naturalists to breed the species and test Mr. Marshall's hypothesis. 

 For many years these efforts were unavailing, one chief difficulty 

 being the ignorance of the early stages and the larval food-plant. 

 At length, in 1909 Mr. A. D. Millar — a distinguished Durban 

 naturalist, whose recent death is a severe blow to African zoology 

 — discovered the food-plant and bred both forms from the eggs laid 

 by a female wahlbergi and later by a female mima.] His results 

 suggested, although they did not prove, that mima was a Mendelian 

 dominant, and wahlbergi recessive. There can be little doubt, as in 

 P. dardanus, that the mimic of dominicanus is ancestral as compared 

 with that of echeria and its ally. If we consider the genus Hypo- 

 limnas as a whole, especially the Madagascar species and the males 

 that have not been modified by mimicry, we are led to conclude that 

 the pattern of wahlbergi is nearer to the general type than mima. 

 This affinity is especially indicated by the prevalent blue scales on 

 the border of the white patches. Professor Punnett has discussed 

 walhbergi and mima and their models on pp. 134 — 5 of the latest 



* trans. Ent. Soc, 1902, pp. 491 — 2. 

 f Vroc. Ent. Soc., 1910, pp. xiv — xvi. 



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