332 PROCEEDINGS OF THE ACADEMY OF [June, 



African, and British birds experimented with are not well known, 

 for the selectionists have examined very few stomachs of wild birds. 

 This method is more arduous and does not pile up results so hand- 

 somely as do experiments. But it is, nevertheless, in connection 

 with the strictly correlated examination of contents of other parts 

 of the alimentary canal, and of pellets, and faeces (together with 

 reliable records of individuals seen or collected with food in talon or 

 beak), the only trustworthy method of learning what birds actually 

 eat under natural conditions. And this information only is accep- 

 table proof of the tastes and food preferences of birds or, for that 

 matter, of any other animals. 



It is fortunate, therefore, that one series of experiments has been 

 made the results of which can be closely checked with a satisfactory 

 amount of exact information upon the food habits of the same species 

 under natural conditions. 



Experiments by Judd and Beal. 



The experiments referred to have never been published upon as a 

 whole, though some of the results may be found in the following 

 publications : 



Beal, F. E. L. The Bluejay and its Food. Yearbook U. S. Dept. 



Agr., 1896 (1897), pp. 205, 206. 

 Birds of California in relation to the Fruit Industry. Part I, 



Bui. 30, Biol. Survey, 1907, p. 35. 

 Judd, Sylvester D. Four common Birds of the Farm and Garden. 



Yearbook U. S. Dept. Agr., 1895 (1896), pp. 410, 414. 

 The Efficiency of some Protective Adaptations in securing 



Insects from Birds. Am. Nat., 33, No. 390, June, 1899, pp. 



461-484. . 

 The relation of Sparrows to Agriculture. Bui. 15, Biological 



Survey, 1901, pp. 45-48. 

 The Bobwhite and other Quails of the United States in their 



economic relations. Bui. 21, Biological Survey, 1905, pp. 



28, 29, 36, 38, 40, 41, 44-45. 



Doctor Judd was at one time yery enthusiastic with regard to 

 experiments in feeding birds, and these experiments were initiated 

 and largely carried on by him. They were watched, however, and 

 in part performed by Prof. F. E. L. Beal, the veteran economic 

 ornithologist, who has examined the contents of more bird stomachs 

 than any other person in the world. Prof. Beal was mainly respon- 

 sible for the discontinuance of these experiments, and I am betraying 

 no secret in asserting that experimental ornithology was abandoned 



