— 155 — 
M. E. B. Boulton (Oxford) prend ensuite la parole pour exposer: 
Mr. C. A. Wiggins’ researches on mimicry in the Forest 
Butterflies of Uganda (1909). 
( Résumé .) 
1 
The memoir printed in the second part of this volume contains 
an account of Mr. Wiggins’ admirable observations on a certain 
dominant of Planema- models ( Acrœinæ ) and their numerous 
mimics, between May 23rd, and August 31st, 1909. These models 
provide three very different and clearly defined patterns. The 
captures were made in a patch of virgin forest, near Entebbe, on 
the north-west shore of the Victoria Nyanza, and the results of at 
least thirty days work are tabulated for each of the three patterns 
with their mimics. We thus obtain the most conclusive evidence 
that model and mimics fly together, for they were taken in the 
same area and on the same da) r s. 
The three combinations are as follows : 
I. The male of Planema macar is ta and both sexes of PI. poggei 
with their mimics : the female of Acrœa alciope, the male of 
Pseudacrœa hobleyi, both sexes of Ps.kuenowi , and the female form 
planemoides of Papilio dardanus dardanns. Incipient mimicry is 
also found in some individuals of Pseudacrœa albostriata , throwing 
light upon the origin of mimetic resemblance. Occasional females, 
of A. alciope resemble a western type, mimetic of the common 
appearance of western male Plajiemas. They make us to under¬ 
stand how a mimetic form may assume a new pattern in an area in 
which it meets a new and dominant model, and how the older 
pattern may be gradually eliminated in that area. Of the two 
mimetic Pseudacrœas, Ps. hobleyi c? more closely resembles 
PI. macarista çf, while Ps. kuenowi resembles PI. poggei. A single 
female of Ps. hobleyi possessing the mimetic pattern of the male 
was captured May 18th, 1909. The relative abundance of models 
and mimics in this and the two following combinations has an 
important bearing on theories of mimicry. 
Two interesting mimics belonging to this association were not 
captured by Mr. Wiggins in the period under consideration : a 
local form of Elymnias phegea , and the female of Precis rauana. 
