74 MIMICRY, AND OTHER PROTECTIVE 
and polished coat of mail which may render them 
unsatisfactory food to such birds as would be able to 
capture them. The causes which lead to the develop- 
ment of colour have been here able to act unchecked, 
and we see the result ina large variety of the most 
gorgeously-coloured insects. 
Here, then, with our very imperfect knowledge otf 
the life-history of animals, we are able to see that 
there are widely varied modes by which they may 
obtain protection from their enemies or concealment 
from their prey. Some of these seem to be so com- 
plete and effectual as to answer all the wants of the 
race, and lead to the maintenance of the largest pos- 
sible population. When this is the case, we can well 
understand that no further protection derived from a 
modification of colour can be of the slightest use, and 
the most brilliant hues may be developed without any 
prejudicial effect upon the species. On some of the 
laws that determine the development of colour some- 
thing may be said presently. It is now merely neces- 
sary to show that concealment by obscure or imitative 
tints is only one out of very many ways by which 
animals maintain their existence; and having done 
this we are prepared to consider the phenomena of 
what has been termed “ mimicry.” It is to be par- 
ticularly observed, however, that the word is not here 
used in the sense of voluntary imitation, but to imply 
a particular kind of resemblance—a resemblance not in 
internal structure but in external appearance—a resem- 
blance in those parts only that catch the eye—a re- 
