304 
COLOUR IN NATURE 
CHAP. 
purpose. Another example of a similar elaboration 
of protective resemblance may be also quoted from 
Mr. Poulton’s pages. The insect in this case was 
found by Mr. W. L. Sclater in Tropical America. In 
the place where it was found the leaf-cutting ants are 
extremely numerous, and are constantly seen carrying 
pieces of leaves “ about the size of a sixpence held 
vertically in the jaws.” The insect found by Mr. 
Sclater, though not an ant, resembled one; and, 
moreover, had an anterior, thin, flat expansion which 
imitated the leaf carried by the ants, so that, as a 
whole, in Mr. Poulton’s words, the insect t£ mimicked 
the ant, together with its leafy burden ” {ibid. pp. 
252, 253). Now, as it is only the homeward-bound 
ants which carry pieces of leaves, it seems in 
this case also that the protective resemblance is 
unnecessarily laborious ; something less might surely 
have served. 
Apart from this, however, the examples show how 
some naturalists attack the problems of colour. It 
is unnecessary here to go into further detail as to the 
various applications of the theory ; most of these have 
now become completely popularised. 
2. Mr. Wallace's Theory—We shall next pass on 
to consider the modification of this theory which is 
supported by Mr. A. R. Wallace. Mr. Wallace, in his 
book on Darwinism, expresses his general belief in 
the theory of colour production implicit in such terms 
as Mimicry, Warning Coloration, etc., and dissents 
only from the theory of the origin of the bright 
colours of males by Sexual Selection. In point of 
fact, however, his dissent in reality carries him further 
than this, and to some extent at least shakes the 
