( iv ) 



that whereas in all the other species the 9 $ s were some 

 shade of green similar to the c? cj s, the Bourbon insect was 

 more or less uniformly brown. He suggested that this was 

 due to mimicry, Euploea goadoti, a species strictly confined to 

 Bourbon, being the model. The case had been dealt with more 

 fully and the insects figvired in his paper on " The bvitterflies 

 of Mauritius and Bourbon," in the Transactions 1907. 



Mimicry in the Butterflies of Mauritius and Bourbon. — 

 Professor E. B. Poulton, F.R.S., exhibited a series of species 

 of the Papilio nireus group from many parts of Africa, froife- 

 Madagascar, Mauiitius and Boui'bon, together with other 

 Rhopalocera from the two latter islands bearing on the subject 

 of mimicry. He said that his attention had been directed to 

 the difficult and fascinating problems presented by these small 

 outlying islands by the lecent inteiesting observations and 

 experiments of Colonel N. Manders, to whose kindness he 

 owed the opportunity of exhibiting some of the spec- niens. 



The black blue-marked upper-surface of the wings ^n the 

 numerous species and siib- species of the Papilio nireios group 

 presented a singularly uniform and characteristic appearance 

 throughout Africa and Madagascar. It appeared probable to 

 the speaker that these forms constituted a definite Ethiopian 

 synaposematic gioup. One of the species {epiphorhas, Boisd.) 

 in Madagascar had, however, spread into Mauritius as Papilio 

 manlius, F., and into Bourbon as P. pkorbanta, L. {disparilis, 

 Boisd.). These two island-forms were entirely separated 

 geographically from other members of their abundant and 

 dominant group, while they at the same time came into 

 contact with Euplceas of a characteristic Oriental type of colour- 

 ing, with E. eihphone, F., in Mauritius, with E. (joudoti, Boisd., 

 in Bourbon. Under these circumstances the dark ground- 

 colour of the female Papilio in Mauritius has faded to a 

 brown shade not unlike that of the EapUe,a, while the blue 

 markings have lost their sharp outlines and have become 

 slightly reduced in size as compared with those of the male. 

 The mimicry is, of course, in a very incipient stage — so 

 incipient, indeed, as to be probably unrecognisable were it 

 not for the far more complete resemblance attained by the 

 female of phorhanta in Bourbon. With this latter female 



