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 feces (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: 
Brau, 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, 
Bul. 30, Biol. Survey, 1907, p. 35. 
Jupp, SyLvestErR 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. Bul. 15, Biological 
Survey, 1901, pp. 45-48. 
The Bobwhite and other Quails of the United States in their 
economic relations. Bul. 21, Biological Survey, 1905, pp. 
28, 29, 36, 38, 40, 41, 44-45. 
Doctor Judd was at one time very 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 
