INDEX 
A 
Acoustic Filter, A Variable Single Band, G. W. Stewart 150 
Acoustic Wave Filters, Attenuation Factor in, H. B. Peacock... 155 
Acoustics, Nodal Distances in, G. W. Stewart 149 
Ames, See Birds, Rarer. 
Apple, See Ceresa bub alls. 
Attenuation Factor, See Acoustic Wave Filters. 
Austria, See Dolomites. 
B 
Bakke, A. F., and Pammel, F. Ft., The Effect of Weeds Upon Crop 
Production 271 
Baldwin, Francis Marsh, Simultaneous Fast and Slow Drum Records 
of Fatigue 199 
Balmer Fines, See Hydrogen. 
Bell’s Turtle, See Turtle. 
Berry, June, A Comparative Study of the Red-Seeded and Common 
Dandelion 313 
Bios, See Yeast. 
Birds, Rarer, of the Ames Region, H. E. Ewing 211 
Birds, Trapped and Banded, Behavior of, Dayton Stoner 225 
Black River, See Brachiopods, Black River. 
Bowlders, Quartzose, in Kansan Drift at Centerville, Ben H. Wilson. . 121 
Brachiopods, Certain Rhynchonellid, from the Devonian of Iowa, 
Status of, A. O. Thomas and M. A. Stainbrook 93 
Brachiopods, Some Black River, from the Mississippi Valley, C. F. 
and Mildred A. Fenton 67 
Bunsen Flame, See Salt Vapors. 
Carbon, See X-rays. 
Catnip, See Mosaic, Cucurbit. 
Centerville, See Bowlders. 
Ceresa bubalis, Injury to Apple by, J. C. Goodwin and-F. A. Fenton. . 229 
Coal, See Pyrite. 
Conard, Henryj S., A Manual of Ferns and “Fern-allies” of Grinnell 
and Vicinity 317 
Conard, Henry S., A Manual of the Gymnosperms “Evergreens” of 
Iowa, Both Native and Cultivated 328 
Conglomerates, Fimestone, Origin of, Fouise Fillman 128 
Copper Films, See Hall Effect. 
Corn, Nodal Infection of, by Dipodia zeae, F- W. Durrell 346 
Cosmology, see Universe. 
