Function of Vitamin B1 in Anaerobic Bacterial Metabolism. M. Silverman and C.H. Werkman pages 107-114

The Dehydration of Cholesterol. J.C. Eck and Ralph L. Van Peursem pages 115-128

Reuteria Puton; Four New Species from the United States (Hemiptera Miridae). Harry H. Knight pages 129-134

High Molecular Weight Fatty Acid Derivatives I. Characterization of Acids. henry Gilman and Grover M. Ford pages 135-148

Studies on the Fat of Chedder Cheese. C.B. Lane and B.W. Hammer pages 149-156

Pressure-Aeration Effects on the Dissimilation of Glucose by Aerobacter Indologenes. M.N. Mickelson and C.H. Werkman pages 157-160

Decomposition and Gas Production of Cornstalks Under Anaerobic Conditions at 28 to 30 Degrees Celsius. G.H. Nelson, Robert P. Straka, and Max Levine pages 161-180

New Species of Psyllidae from the Western United States. L.D. Tuthill pages 181-186

A Comparison of Spring Migrations of Some Birds Through Clay and Palo Alto Counties, Iowa. Jessop B. Low pages 187-200

The Cicindelidae of Iowa. (Coleoptera). Dean E. Eckhoff pages 201-230

The Distribution of Symmetric Quadratic Forms in Normal and Independent Variables. Gerhard Tinter pages 231-234

The Effect of the Ingestion of Irradiated yeast, Molds, and Ergosterol on the Antirachitic Potency of Ewe's Milk. William Gordon Kirk pages 235-238

Noteworthy Additions to the Collection of Mammals from Iowa in 1938. Thos. G. Scott pages 239-242

Biological Assay of Feeding Stuffs in a Basal Ration for Coccidium-growth-promoting Substance. III. Dried Fish Meal, Alfalfa Meal, White Wheat Flour. Elery R. Becker and Phillip C. Waters pages 243-248

Factors Affecting the Milk Production of Simmenthaler Grade Cows Under the Penkeeping System. Geraldo O. Carneiro pages 249-268

A Gas-Type X-Ray Tube. L.E. Pinney pages 269-274

Occurrence of Acrolein as an Intermediate During the Fermentation of Glycerol by the Coli-aerogenes Bacteria. Howard Reynolds, W.M. Hoehn, and C.H. Werkman pages 275-278

The Effect of the Concentration of Mannitol upon the Production of Levulose by the Action of Aerobacter suboxydans. E.I. Fulmer, J.W. Dunning, and L.A. Underkolfer pages 279-282

Equipment for Radiography with Soft X-Rays. F.M. Bailey and G.W. Fox pages 283-292

Some Experiments with Fertilizers for Evergreen Seedlings. J.A. Larsen and W.G. Stump pages 293-312

Strongylocoris Blanchard: Six New Species from North America (Hemiptera, Miridae). harry H. Knight pages 1-8

The Formation of Vitamins A,B1, and C In Lemna grown in the Absence of Organic Matter. Norman A. Clark, B.H. Thomas, and E.E. Frahm pages 9-16

A Method for recording Evaporation from a porous Atomometer Cup. L.A. Richards and M.B. Russell pages 17-20

The High Frequency Glow Dishcarge in Hydrogen Excited Through internal Electrodes. G.W. Fox and N.T. Burdine pags 21-26

Lower Cost Diets for Hatchery trout. W.W. Aiken pages 27-34

Abstracts of Doctoral Theses. pages 35-106

Action of Micro-organisms on Fats. I. The Significance of Color Changes in Dyes Used for the Detection of Microbial Action on Fat. C.H. Castell and L.R. Bryant pages 313-328

A Study of Cholesterilene. J.C. Eck and E.W. Hollingsworth pages 329-334

Notes on Typha angustifolia L. in Iowa. Ada Hayden pages 341-352

The Effect of Treated Fats on Vitamin A Potency. R.T. Harrelson, P. Mabel Nelson, Belle Lowe, H.C. Dyne, and V.E. Nelson pages 353-264

Thiamin Effects in Bacterial Metabolism. M. Silverman abd C.H. Werkman pages 365-368

Asymptotic Solution of a Boundary Value Problem. Erich Rothe pages 369-372

The Theory of Topological Order in Some Linear Topological Spaces. Erich Rothe pages 373-390

Index to Volume XIII pages 391-396