Pscudacrtea poggei and Limnas chrysippus. 205 



is found, but in this whole series of seventeen specimens 

 of poggei no individual shows any resemblance to dorippus : 

 it is purely a mimic of chrysippus and shows no approach 

 to dimorphism. This is explainable on the ground that it 

 is found only where chrysippus is the largely predominant 

 form, and, so far as is known, it does not occur in, or has 

 not yet reached, the parts where dorippus is relatively 

 abundant — that is, the desert strip along the E. Coast, 

 extending in the E. African Protectorate inland at least to 

 the shores of Victoria Nyanza. In this respect it com- 

 pares in an interesting manner with misippus ^, of which 

 the inaria form, mimicking dorippus, is found all over 

 Africa (Trans. Ent. Soc. Lond., 1902, pp. 473-484): and 

 also with Acrssa cncedon, L., var. daira, G. and S., which 

 is only frequent in localities where its type dorippus is 

 predominant (1. c. pp. 473-484). 



This occurrence in considerable numbers of what has 

 hitherto been regarded as the rarest species of Pscudacr&a 

 supports the hypothesis that the mimics of this group are 

 Mullerian rather than Batesian. This has already been 

 argued for H. misippus (cf. Rep. Amer. Assoc. Adv. Sci. — 

 Detroit, 1897 ; and Trans. Ent. Soc. Lond., 1902, pp. 480 

 and 483, with references) as well as for the genus Pscuda- 

 crma and for A. cncedon (pp. 480, etc.). The fact that 

 the latter species, belonging to a protected and much- 

 mimicked subfamily, is far more coincident geographically 

 with the corresponding forms of its model II misippus 

 % is obviously a powerful argument in favour of the 

 Mullerian interpretation. 



Note by Professor E. B. Poulton, F.R.S. 



It is deeply interesting to compare the details of the 

 mimetic resemblance borne by Pseudacrsea poggei to 

 Limnas chrysippus with those of the other great Nympha- 

 line mimic — Hypolimnas misippus $. Almost all the 

 points in the following statement can be verified by 

 means of the half-tone reproductions of the three species 

 on the accompanying Plate XIV. It is to be observed, 

 however, that Fig. 1 represents a £ chrysippus with five 

 wings, a second smaller left hind-wing concealing the 

 central portion of the normal hind-wing of the same side. 



