SUBJECT INDEX 
. PAGE 
Acid Pot€LSsium and Acid Sodium Phthalates as Standards in Alkalimetry 
and Acidimetry, W. S. Hendrixson 217 
Advertisements, Measurement of Merit of. Psychology Applied to, Harry 
H. Gould 339 
Armillaria, Bxobasidium on, Guy West Wilson 134 
Barite in Lead and Zinc District of Iowa, Illinois and Wisconsin, Oc- 
currence of, W. D. Shipton 237 
Bessey,” Dr. Charles Edwin, L. H. Pammel. 12 
Binaural Beats, Theory of, G. W. Stewart and Harold Stiles 18 
Building Materials, Some Well Known, Nicholas Knight 213 
Cell, Standard, A Convehient, Dieu Ung Huong and J. N. Pearce. 169 
Cephalopods, Niagaran, Some Unique, A. O. Thomas 292 
Change of Lamp Voltage, Effect of, on Vision, Wm. Kunerth 333 
Coal-Washing Plant in -Iowa, First, George P. Kay 225 
College Museum, Building and Function of, B. H. Bailey 358 
Condensers, Phase Difference of. Resonance Method for Measuring, H. 
L. Dodge 311 
Crinoid Fauna, New, from Monticello, Iowa, A. O. Thomas 289 
(Crow, The,' Fred Berninghausen 345 
Crystal Phonopticon in its Adaptation to Enable Blind to Read Printed 
Page, P. C. Brown 317 
Drifts of Eastern Iowa, Leaching of, Morris M. Leighton 19 
Electrons, Absence of Liberation or Absorption of. During Changes 
from Conducting to Non-Conducting State, L. E. Dodd 307 
Fauna, Macroscopic, of a Small Brook, D. M. Brumflel 363 
Flora of East Slope of Cascades in Oregon, Morton E. Peck 143 
Forest Trees and Shrubs of Missouri River Basin, L. H. Pammel, G. B. 
MacDonald and H. B. Clark 23 
Geologic Correlation, Exact, Foundation of, Charles Keyes 249 
Heating Apparatus, Improved, for Maintaining Constant Temperatures 
in Work with Polarimeters and Refractometers, J. N. Pearce 165 
Hickory Nut, Anomalous, Guy West Wilson 133 
High Temperature Ovens, Electrical Regulation' of. Design for, W. E. 
Tisdale 301 
Houghtelin, Rev. David MacMillan, John L. Tilton 14 
Iowa Locality Records, Early, B. Shimek 105 
Ledges Region of Boone County, Iowa, Flora of, Wm. W. Diehl 77 
Loess of Peczel, Hungary, B. Shimek 285 
Nectar Production, Notes on, L. A. Kenoyer 129 
4-Nitro-5-Methyl-2-Sulphobenzoic Acid and Some of Its Derivatives, Wm. 
J. Karslake and Perry A. Bond.... 175 
Pentatomoidea, Iowa, Notes on, Dayton Stoner 347 
Phosphor Bronze Wires, Certain Elastic Peculiarities of, L. P. Sieg and 
A. J. Oehler ’ 321 
Pioneer Plants on a New Levee, Frank E, A. Thone 135 
Pitch of Voice in Singing, Control of. Psychology Applied to Improve- 
ment of, Carl J. Knock 337 
Prairie Plants, Ecological Histology of, Ella Shimek 121 
Prairie Spotted Skunk, Distribution of, in Iowa, B. H. Bailey 355 
Prairie Synclinorium, Remarkable, Charles Keyes 268 
Ragweed, A Hybrid, Robert B. Wylie I 27 
Rainy River Region, Flora of, Harriette S. Kellogg 60 
Rat, Lymphatic System of, Thestle T. Job Ig 
