124 MIMICRY, AND OTHER PROTECTIVE 
complete. We now enter upon a new phase of the 
phenomena, and come to creatures whose colours neither 
conceal them nor make them like vegetable or mineral 
substances; on the contrary, they are conspicuous 
enough, but they completely resemble some other 
creature of a quite different group, while they differ 
much in outward appearance from those with which 
all essential parts of their organization show them 
to be really closely allied. They appear like actors 
or masqueraders dressed up and painted for amuse- 
ment, or like swindlers endeavouring to pass them- 
_ selves off for well-known and respectable members 
of society. What is the meaning of this strange 
travestie? Does Nature descend to imposture or mas- 
querade? We answer, she does not. Her principles 
are too severe. There is a use in every detail of 
‘her handiwork. The resemblance of one animal to 
another is of exactly the same essential nature as the. 
resemblance to a leaf, or to bark, or to desert sand, 
and answers exactly the same purpose. In the one 
case the enemy will not attack the leaf or the bark, 
and so the disguise is a safeguard; in the other case 
it is found that for various reasons the creature re- 
sembled is passed over, and not attacked by the usual 
enemies of its order, and thus the creature that 
resembles it has an equally effectual safeguard. We 
are plainly shown that the disguise is of the same 
nature in the two cases, by the occurrence in the 
same group of one species resembling a vegetable 
substance, while another resembles a living animal of 
