ADAPTATION FOR THE SPECIES 131 
These creatures are in the habit of resting in the day- 
time against walls, or stones, or the bark of trees. 
The similarity in color between their front wings, 
which alone show while sitting, and the background 
on which they rest, is most remarkable. One may 
pass them again and again, although they are of con- 
siderable size, and not notice them at all. Once let 
them display their hind wings and the brilliancy of 
their color always attracts immediate attention. 
It is among birds, however, that brilliant coloration 
serves its most effective purpose. The birds are alert, 
exceedingly quick of sight, and are much more dis- 
criminating than insects in almost every respect. It 
is not so impossible that these creatures might even 
voluntarily prefer a distinctly more brilliant mate, 
though the voluntary character of the process is not 
essential to its success. Men certainly are constantly 
attracted to women for whose charm it would puzzle 
them to account. If this is true with regard to men, 
it is certainly probable that birds would be largely in- 
fluenced by phases of attractiveness, of which they 
were observant, but unconscious. 
Certain it is that in many birds the males are far 
more beautiful than the females. Perhaps the com- 
monest illustration, and, at the same time, one of the 
best is found in the so-called red-wing or swamp 
blackbird. The male of this creature is a brilliant 
