TITLES OF PAPERS RECEIVED 



The number following a title indicates the page of the Proceedings 

 on which it may he found. 



President's Address: Does the History of Science Have a 



Place in the College Cirriculum? L. S. Ross 33 



Physics and Psychology. 



Page 



Temperature-Time Relations in Canned Foods During Sterili- 

 zation George E. Thompson 39 



(a) Some Structural Features of Selenium Deposited by Con- 

 densation from the Vapor State above the Melting Point, 

 (b) The Sublimation Curve for Selenium Crystals of the 

 Hexagonal System L. E. Dodd 



Stroboscopic Velocities in the Tonoscope 



H. R. Fossler and L. E. Dood 49 



The Eclipse Expedition to Matheson, Colorado, June 8, 1918 

 D. W. Morehouse 



The X-Ray Spectrum of Tungsten 0. B. Overn 59 



A New Principle in the Design of Rheostats of Large Capacity 

 H. L. Dodge 



On the Coefficient of Absorption of Photoelectrons in Silver 



and Platinum Otto Stuhlman, Jr 61 



On the Production of Opaque and the Color of Transparent 

 and Semitransparent Metallic Films.. Otto Stuhlman, Jr. 



Hall Effect in Thin Silver Films G. R. Wait 



The Effect of Pressure upon the Conductivity of Selenium. . . . 

 E. O. Dieterich 



The Measurement of Basic Capacities in Motor Ability 



Carl E. Seashore 67 



Zoology and Allied Subjects. 



Bird Records of the Past Winter a917-191S) in the Upper Mis- 

 souri Valley T. C. Stephens 71 



A Note on Molluscan Behavior T. C. Stephens 



Birds of Union County, South Dakota T. C. Stephens 85 



An Unusual Example of Incisor Growth in the Western Fox 



Squirrel Dayton Stoner 105 



Pharyngeal Derivatives of Amblystoma 



Francis Marsh Baldwin Ill 



Economic Entomology and Food Conservation 



R. L. Webster 117 



A List of the Birds Found in Marshall County, Iowa 



Ira N. Gabrielson 123 



The Influence of Floods upon Animals D. M. Brumfiel 155 



Notes on a Wood Borer H. E. Jaques 175 



The Life and Behavior of the House Spider H. E. Ewing 177 



A Preliminary List of the Acarina of Iowa. . . .Albert Hartzell 205 



