1908. Food Habits of the Grosbeaks. U. S. Dept. Agr., Bur. Biol. Surv., Bull. 32. pp. 92.

1913. Index to Papers Relating to the Food of Birds by Members of the Biological Survey in Publications of the United States Department of Agriculture, 1885-1911. U. S. Dept. Agr., Biol. Surv., Bull. No. 43. pp. 69.

The Bureau of Biological Survey, and its predecessor, the Division of Ornithology and Mammalogy, have published in the Annual Reports and in numerous bulletins elaborate studies of the foods and habits of birds and mammals.

Rauschenplat, E.

1901. Ueber die Nahrung von Thieren aus der Kieler Bucht. Wiss. Meeruntersuch. heraus. von der Komm. zur wiss. Unter. der deutsch. Meere in Kiel. N. F. Bd. V, Abth. Kiel, pp. 85-151.

Riley, C. V.

1893. Parasitism in Insects. Proc. Ent. Soc. Wash., Vol. II, pp. 397-431.

Stiles, C. W.

1893. Parasitism. Proc. Ent. Soc. Wash., Vol. III, pp. 1-7.

Stiles, C. W., and Hassall, A.