— 183 — 
dissent from the anti-mimetic views arrived at by M. Schaus as 
expressed in the paper just read. He asked how it was possible, 
for instance, to explain the evolution of the many mimetic forms 
of the female of the African Papilio dardanus , which in each 
sub-region imitated with exactness a corresponding number of 
widely-differing species of unpalatable models, as the result of 
either common external geographical conditions, or of simul¬ 
taneously acting internal causes. 
M. Trimen also observed that M. Schaus had cited instances in 
which the flight of the mimicking Butterfly differed from that of 
the species mimicked; but there were, on the other hand, many 
cases on record in which the mode of flight of the model, as well 
as its outline and colouring, has been very closely simulated by the 
mimic. 
In the important matter of persecution by insectivorous enemies, 
if the well authenticated cases on record of Birds seen attacking 
o 
Butterflies are not so numerous as might be expected, this ma}^ 
mainly be due to the fact that most Birds hunt for food eagerly in 
the early morning before sunrise, white Butterflies are still at rest 
and so unnoticed by the human observer, but far more easily 
caught by hungry Birds than when they are on the wing. 
It is quite possible that these attacks by vertebrate enemies on 
Butterflies when the latter are completely at rest, with only the 
under-surface of the wings exposed, are correlated with the fact 
that in nearly all unpalatable species, and also in their mimics (with 
the exception of a certain number in which only the upperside 
is mimetic while the underside is distinctly cryptic), the under¬ 
surface closely resembles the upper-surface in its warning coloration 
and marking and is equally conspicuous. 
Hon. W. Rothschild agreed with M. Trimen that there were 
many facts very difficult to explain under any other assumption 
than that of mimicry. He cited a further instance of Papilio 
laglaizei and the Uranid Moth Nyctale?non agathocles, also a 
day-flyer and met with in company of the Papilio. The abdomen 
of this Moth is brilliant orange underneath, while the Papilio only 
has an orange patch on the underside of the hind wing, but this, 
when the wings are folded, gives quite the impression of an orange 
abdomen. 
He also cited the case of the two parasites of the Rhinoceros 
and the Elk, which mimic well protected Hymenoptera. 
