APPENDIX IV. 339 



1880. FORBES, S. A. On Some Interactions of Organisms. Bul- 

 letin Illinois State Laboratory Natural History, vol. i., 

 pages 3-17. 



A general discussion of the food relations of animals, with 

 especial reference to birds and insects. 



1880. FOKIJKS, 8. A. Xotes on Insectivorous Coleoptera. Bul- 

 letin Illinois State Laboratory Xatural History, vol. i., 

 pages 153-1 GO. 



Feeding habits of ground-beetles, with discussion of relation 

 to birds. 



1880. FERRIS, EDOUAHD. Birds vs. Insects. American Ento- 

 mologist, vol. iii., pages 69-72, 90-100. 



A translation by S. A. Forbes of an important paper making 

 arguments similar to those of Walsh in 1807. 



1880. WEBSTER, F. M. Xotes upon the Food of Predaceous 

 Beetles. Bulletin Illinois State Laboratory Xatural His- 

 tory, vol. i., pages 149-152. 



Observation on food habits of ground-beetles and others that 

 birds feed upon. 



1881. ALDRICII. CHARLES. Value of the House-Wren as an 

 Insect Destroyer. American Naturalist, vol. xv., page 

 318. 



Hardiness, sociability, love of locality, and wonderful fecun- 

 dity render it one of the most valuable of our insectivorous 

 birds. 



1881. BUMPUS, H. C. The Habits of the Yellow-Bellied Wood- 

 pecker. American Naturalist, vol. xv., page 738. 



A proof that these birds are sap-eaters, if not also bark- 

 eaters. 



