310 PROCEEDINGS OF THE ACADEMY OF {June, 
startling difficulty, yet it is evident from the behavior of the lizards 
that they fully expected the larva to be palatable, in itself a strong 
confirmation of the suggestion that nearly all such larve are palat- 
able” (p. 243). This is another argument that cannot be accepted 
unless it is also applied to the rejections of conspicuous larve upon 
trial, and this latter evidence rather than disregard is all the experi- 
ments yield that is worth any consideration. In fact, if impartially 
applied, this argument would do away with the experimental evidence 
of the efficacy of warning colors in all cases in which the insects were 
tasted before refusal. In other words, it would be just as fair to 
presume that these conspicuous larve also were expected to be 
palatable, “in itself a strong confirmation of the suggestion that 
nearly all such larve are palatable.” 
The experiments performed by R. I. Pocock, Superintendent of 
the London Zoological Gardens, like those just reviewed, cover a 
variety of vertebrate orders. A far larger number of species both 
of predators and prey were used than in any other experiments yet 
recorded. The captive animals included twenty-six species of 
mammals, ninety-six of birds, and seven of lizards, of which only 
six birds and one lizard occur naturally in England. The insects 
used were, of course, chiefly native. Even if we believe that experi- 
mental results have any value as indicating natural behavior, we 
can only conclude that the conditions of these experiments invalidate 
the findings, for of what possible value can it be to know the likes 
and dislikes of exotic animals for British insects? 
The account of these experiments is in P. Z. S. Lond., 1911, pp. 
809-864. Mr. Pocock thinks his experimental results have ‘an 
important bearing upon the criticism sometimes advanced against 
the theory of warning coloration and mimicry as applied to butter- 
flies, namely, that birds under natural conditions are seldom seen to 
eat these insects. Hence it has been inferred that birds cannot be 
reckoned as serious enemies of butterflies. Whatever may be the 
explanation of the circumstance,” Pocock says,-‘‘I am tolerably 
sure, from the behavior of the two classes of animals when pitted 
against one another that the inference drawn therefrom is erroneous. 
The insectivorous birds in our aviaries seemed to know at once what 
the butterflies were; they were on the alert the moment one was 
liberated and pursued it with determination and precision, following 
its every turn and twist, and either catching it upon the wing or 
pouncing upon it after settling. It is true that this predatory 
deftness may have been acquired in relation to the chase of insects 
