( iv ) 



that wliereas in all the other species the ? + s were Rome 

 shade of green .similar to the ^ 6 s, the Bourbon insect was 

 more or less uniformly brown. He suf,'gestod that this was 

 due to mimicry, IJuphca f/ondoti, a species strictly confined to 

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

 fully and the insects figured in his paper on " The butterflies 

 of Mauritius and J)Ourl)on," 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 nireits group from many parts of Africa, from 

 Madagascar, Mauritius and 15ourl)on, together with other 

 Rhopalocera from the two latter islands bejiring on the subject 

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

 the difiicult and fascinating pioblems presented by these small 

 outlying islands by the recent interesting observations and 

 experimezits of Colonel N. Manders, to whose kindness he 

 owed the opportunity of exhibiting some of the specimens. 



The black blue-marked upper-surface of the wings in the 

 numerous species and sub-species of the raqnlio nirens group 

 presented a singularly uniform and characteristic appearance 

 throughout Africa and Madagascar. It appeared proI)able to 

 the speaker that these forms constituted a definite Ethiopian 

 synaposematic group. One of the species [epiphorbas, Boisd.) 

 in Madagascar had, however, spread into Mauritius as Papilio 

 nianlius, ¥., and into Bourbon as P. phorhanla, L. (disparilis, 

 I'loisd.). These two island-forms were entirely separated 

 geographically from other members of their abundant and 

 dominant group, Avliilo they at the same time came into 

 contact with Eiipheasoi a churaci-eristic Oriental type of colour- 

 ing, with E. euphone, F., in Mauritius, with E. (joiuloli, Boisd., 

 in Bourbon. Under these circumstances the dark ground- 

 colour of the female I'apilio in Mauritius has faded to a 

 brown shade not unlike that of the Eapkea, 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 probal)ly unrecognisable were it 

 not for the far more complete resemblance attained by the 

 female of phorbanta in Bourbon. With this latter female 



