A COMMON AMERICAN CASE OF MIMICRY 
These two butterflies are familiar to everyone who has observed insects in the United 
States, and are generally regarded as offering an example of mimicry. 
coloring, a rich brown and black, is even more similar than their pattern. 
Their 
Below 
is the Monarch butterfly (Danais archippus) which is supposed to be unpalatable 
and shunned by birds after they have had one taste; above is the Viceroy 
(Limenitis archippus) belonging to a totally different family which is supposed 
to be edible. 
By mimicking the appearance of its larger and distasteful neighbor, 
it is supposed that the Viceroy secures protection from attacks by birds. 
Photographs natural size. (Fig. 8.) 
agreeable taste. Such Pierines would 
therefore have a rather better chance of 
surviving and of leaving offspring. 
Some of the offspring would exhibit 
the variation in a more marked degree 
and these again would in consequence 
have a yet better chance of surviving. 
Natural selection would encourage those 
varying in the direction of the Ithom1- 
ine model at the expense of the rest and 
by its continuous operation there would 
be built up those beautiful cases of 
resemblance which have excited the 
admiration of naturalists.”’ 
465 
