Appendix (4d) 
Bibliography 
(Note: This does not purport to be a complete list of the refer- 
ences pertinent to the subjects discussed. It is merely a list 
of those encountered and used as sources of facts.) 
(1) 
(2) 
(3) 
(4) 
(5) 
(6) 
(7) 
Ornithology 
Ridgeway, Robert. 1874, “Catalogue of Birds Ascertained to 
Occur in Illinois." 
Nekson, E. W. 1877, “Birds of Northeast Illinois." Essex Inst, 
Ridgeway, Robert and Forbes, 5S. A. 1889-1895, "The Ornithology 
of Illinois.” 
Forbes, S. A. 1907. “An Ornithological Cross-Section of Illinois 
in Autumn.” 
Woodruff, F. M. 1907, “Birds of the Chicago Area.” Natural 
History Survey. 
Musselman, T. E.. April-July, 1921, “History of Birds of Illinois." 
State Historical Society, 
Forbes, S. A. & Gross, A. 0.. 19235, "On the Numbers and local 
Distribution of Illinois Land Birds of the Open Country in Winter, 
Spring, and Fall." Natural History Survey, 
Soils, Geology, Drainage, Agriculture. 
Leverett, Frank, 1898. "The Illinois Glacial Lobe.” U.S.G.S, 
Monogreph 38, {Plate VI. Oppostie page 24), 
Mosier & Gustafson. 1918. “Washing of Soils and Methods of Pre- 
vention." Bull. 27, Agric. Experiment Station, 
Pickels, G. W. & Leonard, F. B, Jr., 1921, “Engineering and Legal 
Aspe ae of Drainage in Illinois.” State Geol, Survey. (Being revised 
for /b blication). 
Flint, W. P. 1922. “Burn the Chinch Bug.” Agric. Exp. Sta. 
Circular 265. 
Flint, W. P., et al. 1928. “learning to Live with the European 
Corn Borer." Agric. Exp. Sta. Circular, S21. 
Hopkins, Mosier, Van Alstine, Garret, Smith, Stewart, et al: 
"Soil Reports” by counties, Univ. of Ill., Agric. Exp. Station, 

