ASS 
When a particular pattern is restricted to one sex in both model 
and mimic, it is common for the female to resemble a female, the 
male a male. Thus the likeness founded on similarity of pattern is 
heightened by similarity in the habits and movements which are 
characteristic of sex. A good example is afforded by Pseudacrea 
hobleyi with its male mimicking a male Planema and its female 
the female of the same Planema. The female of Acrwa alciope is a 
well-marked exception to this rule; for on the tropical west coast 
of Africa it mimics the dark male Planemas of the type of 
PI. alcinoe, while at Entebbe its aurivilli female mimics the male 
of Pl. macarista. There can be no doubt that the western females 
are ancestral as compared with those at Entebbe; for the displace- 
ment of the older form is not complete. Thus, in addition to the 
49 alciope females recorded in Table I, 2 specimens, captured on 
August 14th and 1 on August 18th, are modifications of the western 
type, perhaps altered by incipient mimicry of Planema tellus platy- 
xantha JORD., or by secondary mimicry of the Zellus-like females 
of Acrea jodutta F. The presence of modified western forms of the 
female a/ciope side by side with its other females, that are mimics 
of the male Pl. macarista and both sexes of Pl. poggei nelsoni, is 
extremely interesting. 
Another interesting point is the great relative abundance of the 
mimic. It will be seen by a glance at Table I on pages 486-487 that 
49 mimetic females and 35 non-mimetic males of A. alciope were 
taken in the period under review, together with 93 models : vzz. 
81 males of Planema macarista and 12 examples (11 1 9) of 
PI. poggei nelsoni. The relative numbers of the mimic, its place in 
a highly distasteful group of Butterflies, and the fact that its 
non-mimetic male itself supplies the model for a female Lycænid 
(Mimacrea fulvaria AURIV.) combine to render the aurivillii 
female of A. alciope a remarkably striking example of Müllerian 
or synaposematic resemblance. 
The question indeed arises as to naine the whole of this 
remarkable likeness is to be accounted for by approach on the 
side of the Acrwa or whether the male of Planema macarista has 
not itself undergone some diaposematic change in the direction of 
its mimic. I omit consideration of Planema poggei nelsoni to which 
the aurivillit female bears a much less perfect resemblance. 
There are two features in the pattern, that is common to the 
upper surface of all or many macarista males and all or many 
