MIMICRY, MUTATION AND MENDELISM 



radiates into a whole circle of mimics belonging to a series of remote 

 groups. 



The planemoides female of dardanus, with a broad fulvous bar 

 crossing the fore wing, and a large white patch covering the base 

 of the hind, stands out as very distinct from the other three mimetic 

 forms. Planemoides has not yet been proved by breeding to be a 

 female form of dardanus * but evidence equally strong is fortunately 

 provided by a single specimen captured by Captain T. T. Behrens 

 (1902 — 3) in Buddu, on the west shore of the Victoria Nyanza. 

 In this specimen the pale yellow scales and black markings of the 

 male replace the female pattern on parts of both wings on the left 

 side. The evidence of specific identity is certainly curious and 

 interesting, but it is conclusive. Such a fusion of characters can 

 only occur between the male and female of the same species. 



It is, as I have said, very probable that the relationship between 

 the female forms of dardanus is Mendelian, and that the establish- 

 ment of mimicry in various parts of the range of the species has 

 been greatly facilitated by the fact that the female forms keep true, 

 and do not commonly produce intermediates. Furthermore, in 

 certain other polymorphic mimics, the Mendelian relationship may 

 be accepted as proved. But this acknowledgment of the debt 

 which polymorphic mimicry owes to Mendelian heredity by no 

 means implies acceptance of the view advocated by some Mendelian 

 writers — in particular Professor Punnett — that each mimetic 

 pattern arose, suddenly and complete, as a mutation from the non- 

 mimetic ancestor. To suppose that each of the forms represented 

 in Plate I., Figs. 7, 8, 9 and 10, sprang suddenly into existence from 

 some ancestral non-mimetic female resembling that of P. meriones 

 in Madagascar (Plate II., Fig. 2) — that each of them, without 

 adaptive adjustment, at once matched the patterns of the four 



* Since these words were written, my kind friend, Dr. G. D. II. Carpenter, has 

 obtained twenty-six eggs from a planemoides female on Bugalla, one of the Sesse 

 Islands in the north-west of the Victoria Nyanza. In his last letter I heard that 

 twenty-five caterpillars were thriving and had changed their third skins. We 

 may anticipate that the female offspring will be chiefly or entirely plancmoi'les and 

 hippocoon. 



March 7, 1913. As I correct these proofs I am able to add the result of this 

 most interesting and long-sought-for experiment in breeding. In a letter received 

 this morning, Dr. Carpenter tells me that three female offspring are planemoides 

 and seven hippocoon. 



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