232 ENTOMOLOGY 
place the theory of Batesian and Mullerian mimicry upon a 
substantial foundation of observational and experimental 
evidence. 
In regard to the important question—do birds avoid un- 
palatable insects instinctively or only as the result of experi- 
ence—the evidence is all one way. Several investigators, in- 
cluding Lloyd Morgan, have found that newly-hatched birds 
have no instinctive aversions as regards food, but test every- 
thing, and (except for some little parental guidance) are 
obliged to learn for themselves what is good to eat and what 
is not. This experimental evidence that the discrimination of 
food by birds is due solely to experience, was evidently highly 
necessary to place the theory of mimicry—especially the Mul- 
lerian theory—upon a sound basis. 
Though butterflies as a group are much subject to the at- 
tacks of birds in the tropics, there are very few recorded in- 
stances of this for our temperate region. It may then be 
asked, what advantage does the “ viceroy”’ (Fig. 243, B) gain 
by resembling the “ monarch,” in a region where all butter- 
flies are exempt from destruction by birds? In reply, it may 
be said that the premise of the argument is as yet little more 
than an assumption, because so little attention has been given 
to the relations between birds and butterflies in our own coun- 
try. Or,admitting the premise, it may be said that the resem- 
blance was advantageous once, if not now; and that in any 
event, the departure of archippus from its congeners toward 
one of the Danainz 
tropics—is unintelligible except as an instance of mimicry. 
a famous group of “ models” in the 
Granting that mimicry is upon the whole advantageous, it 
becomes important to learn just how far the advantage ex- 
tends; and we find that mimicry is not of universal effective- 
ness. Even the highly protected Heliconiinzee and Danainz 
are food for some predaceous insects. In this country, as 
Judd has observed, the drone-fly (Eristalis tenax), which 
mimics the honey bee, is eaten by the kingbird and the pheebe ; 
the kingbird, indeed, eats the honey bee itself, but is said to 
