1912.] NATURAL SCIENCES OF PHILADELPHIA. 361 
approximating the natural, or has at least brought them to a state 
of semi-domestication, where in food taking, evidence of health, etc., 
they are at ease, he has small right to dogmatize as to conclusions, 
or presume to make such conclusions the basis of so-called laws of 
animal behavior. Not a little of recent investigations along the 
lines of animal behavior has been vitiated at just this point, and 
must be repeated to be made trustworthy. The amazing mass of 
contradictory results which has loaded the literature of recent 
years is attributable to some extent to this misfortune.’ 
With regard to experimentation with captive birds, Prof. S. A. 
Forbes, the founder of economic ornithology, says? “This evi- 
dently shows only what the bird will eat when restrained of its 
liberty, of such food as may be placed before it, and furnishes few 
data which we can use with safety in making up an account of its 
food in freedom, when foraging for itself. The state of confinement 
is so abnormal for a bird that on this account, also, we can rarely 
reason from its habits in that state to its ordinary habits. This 
method is, therefore, available only for the solution of a few separate 
questions. ”’ 
The assertions of these authors regarding the modifying effects 
of captivity upon behavior apply more pertinently to no set of 
experiments than those which have been conceived to be tests of 
the food preferences of insectivorous animals in relation to pro- 
tective adaptations. 
The writer has asserted that the experiments are not trustworthy 
guides to behavior under natural conditions, and he expects to prove 
this by citing evidence along two lines, viz.: (1) Animals accept in 
captivity articles of food which they not only do not eat in the wild 
state, but with which their species probably has never had experience, 
and (2) animals reject in captivity articles of food which are not only 
occasionally eaten by wild members of the species, but which may be 
very important elements of the subsistence as a whole. 
(1) Acceptances—This point really needs no proof. Universal 
experience with the feeding of all kinds of captive animals confirm it. 
The coarse brown bread (containing oats, shorts and molasses) given 
to the bears, in some zoological parks, the chopped-up beets, carrots, 
potatoes, etc., of which the parrots, cranes, and certain rodents are 
fond, sufficiently illustrate foods relished in confinement by animals 
% Journ. of Animal Behavior, Vol. 2, No. 1, January-February, 1912, pp. 51, 52. 
%* Bul, Ill. State Lab. Nat. Hist., Vol. I, No. 3, 1880, pp. 86, 87. 
