xiv PREFACE 



It is a curious fact that the African butterflies — far 

 less numerous in species than those of the tropical East, 

 and outnumbered even more by the American — should 

 include what are probably the two most remarkable 

 examples of mimicry in the world — Papilio dardanus 

 and Ps. eurytus ; furthermore, that they should illustrate 

 such different aspects of the subject. 



The Swallowtail, dardanus, whose non-mimetic male 

 is accompanied by a very similar non-mimetic female in 

 Madagascar, the Comoro Islands, Somaliland, and Abys- 

 sinia (although two single but different mimetic females 

 were once taken in this last locality), is represented, 

 wherever it occurs on other parts of the African continent, 

 by females entirely different from males, and either 

 mimetic of other butterflies, or, far more rarely, inter- 

 mediates between these mimetic forms, or persistent 

 stages enabling us to retrace the history of their origin. 

 Until 1903 the mimetic females were all believed to 

 resemble the commonest Danaine butterflies of each 

 locality — often mimicking in a single area three different 

 species with widely different patterns. 



This interesting and complicated story became still - 

 further involved, when, on October 7, 1903, the late Mr. 

 Roland Trimen brought before the Entomological Society 

 an account of a new and entirely different female, mimick- 

 ing not a Danaine, but an Acraeine model, belonging to 

 the genus Planema. For some years the new mimic, 

 appropriately named planemoides, was only by strong 

 inference assumed to be a form of dardanus, but definite 

 proof was soon afforded by the study of a specimen 

 captured by Mr. T. T. Behrens, R.E., near the old southern 

 boundary of Uganda on the west shore of the Victoria 

 Kyanja. This single example was, on the left side, a 

 gynandromorph, viz. one of those rare individuals in 

 which the patterns of the two sexes occur combined. 

 In this case parts of the yellow and black non -mimetic 



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