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." 98 



With regard to experimentation with captive birds, Prof. S. A. 

 Forbes, the founder of economic ornithology, says: 99 "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 



98 Journ. of Animal Behavior, Vol. 2, Xo. 1, January-February, 1912, pp. 51, 52. 

 » Bui. III. State Lab. Nat. Hist., Vol. I, No. 3, 1880, pp. 86, 87. 

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