320 
IOWA ACADEMY OF SCIENCE Voi.. XXVIII, 1921 
T 
Terrepleins of Utah's Plateaux, Geological Age of, Charles Keyes.... 54 
Tills at Ames, Three Glacial, John E. Smith 47 
Tones of High Frequency, Measurements of Minimum Audible In- 
tensity of Sound for, C. E. Dane 89 
Trees, See Mississippi Valley Park. 
Tungsten Spectrum, Alpha Lines in “K” Series, Charles Crofutt.... 117 
Tungsten Wires, Effect of Drawing on Crystal Structure of, L. P. Sieg 95 
Utah, See Terrepleins. 
V 
Vagotomy, See Lung Mechanism. 
Viability, See Gamhusia. 
Vibration of Diaphragm, See Hewlett. 
Volcanic Ash, See Ash. 
Wave Filter, See Acoustic. 
Weevil, Clover-Leaf, 1921 Outbreak of, in Iowa, H. E. Jaques 127 
Werner, Herbert R., Methods of Teaching Parasitology 215 
Wounding, See Leaves. 
Wylie, Robert B., Concerning the Capacity of Foliage Leaves to 
Withstand Wounding 293 
Y 
Young’s Modulus, See Selenium. 
