1912,] NATURAL SCIENCES OF PHILADELPHIA. 283 
distastefulness of certain insects and the palatability of others 
consists of the results of experiments. The cry always is to test 
theories under experimental conditions, but there are many things 
which cannot be so tested. The very conditions of captivity and 
the limited choice of food constitute abnormalities which cannot 
fail to distort the food relations of most animals, and so modify the 
results of experiments that they bear little or no analogy to natural 
conditions. 
In experiments play is allowed to the fancy of the experimenter, 
and the interpretation of facial and other expression of the subject 
has often been given more weight than the actual result of the 
experiment, that is, whether the insect was eaten or rejected. R. I. 
Pocock® very frankly admits this, saying, ‘‘It is quite clear that the 
plain record of an insect being eaten is no proof of its palatability. 
Better evidence on this head is supplied by the behavior of the bird 
towards it. After a little experience in the matter, I was able to 
satisfy myself, at all events, as to the approximate correctness of my 
interpretation of the bird’s actions, and to judge thereby of the 
comparative palatability of the insects they tasted.” This is honest 
confession at any rate, but the writer must take issue with this 
author as to the value of interpretation of behavior. ‘The plain 
record of an insect being eaten,’ which he holds up to scorn, may not 
show palatability, but shows something much more definite, namely, 
that the insect is acceptable food. Palatability in the sense used 
by some of the experimenters is entirely a figment of the imagination. 
This is proved by the many cases of refusal in captivity of insects 
which are eaten under natural conditions, and by the misinterpreta- 
tion of the following among other features of the behavior of caged 
birds and other animals. 
Wiping the bill or mouth: If a bird wipes its bill, or a lizard or 
frog its mouth, when it is being experimented with, the action is 
almost always credited as a sign of distaste. Yet nothing is more 
common than to see wild birds wiping their beaks across branches or 
other objects. It occurs at all times, apparently is often done in a 
purely mechanical way, and certainly has no essential connection 
with the taking of food or perception of tastes. 
Dropping and picking up or in any way manipulating the prey 
is another thing usually taken as evidence of unpalatability, but 
nothing could be more at variance with conclusions drawn from 
5 Proc. Zool. Soc. Lond., 1911, p. 810. 
