76 NATURAL SELECTION iit 
brown, so that when on the wing and seen from below they 
are undistinguishable. The curious point, however, is that 
the Accipiter has a much wider range than the Harpagus, 
and in the regions where the insect-eating species is not found 
it no longer resembles it, the under wing-coverts varying to 
white ; thus indicating that the red-brown colour is kept true 
by its being useful to the Accipiter to be mistaken for the 
insect-eating species, which birds have learnt not to be afraid of. 
Mimicry among Mammals 
Among the Mammalia the only case which may be true 
mimicry is that of the insectivorous genus Cladobates, found 
in the Malay countries, several species of which very closely 
resemble squirrels. The size is about the same, the long 
bushy tail is carried in the same way, and the colours are 
very similar. In this case the use of the resemblance must 
be to enable the Cladobates to approach the insects or small 
birds on which it feeds under the disguise of the harmless 
fruit-eating squirrel. 
Objections to Mr. Bates’ Theory of Mimiery 
Having now completed our survey of the most prominent 
and remarkable cases of mimicry that have yet been noticed, 
we must say something of the objections that have been made 
to the theory of their production given by Mr. Bates, and 
which we have endeavoured to illustrate and enforce in the 
preceding pages. Three counter explanations have been pro- 
posed. Professor Westwood admits the fact of the mimicry ~ 
and its probable use to the insect, but maintains that each 
species was created a mimic for the purpose of the protection 
thus afforded it. Mr. Andrew Murray, in his paper on the 
“Disguises of Nature,” inclines to the opinion that similar 
conditions of food and of surrounding circumstances have 
acted in some unknown way to produce the resemblances ; 
and when the subject was discussed before the Entomological 
Society of London, a third objection was added—that heredity 
or the reversion to ancestral types of form and coloration 
might have produced many of the cases of mimicry. 
Against the special creation of mimicking species there are 
all the objections and difficulties in the way of special creation 
