IOWA ACADEMY OF SCIENCE 
TABLE OF CONTENTS 
Page 
Letter of Transmittal . . iii 
Officers of the Academy v 
Members of the Academy vi 
, Table of Contents x 
Report, of the Secretary — 1 
Treasurer’s Report 2 
Report of Committee on Membership 3 
Program . . 4 
The Pollution of Underground Waters with Sewage Through Fissures in 
Rocks 7 
Tramping in Western Washington.... 11 
The Monterey Conifers 19 
Notes on the Flora of Johnson County, Iowa 27 
Sedges of Henry County 103 
A Partial List of the Parasitic Fungi of Decatur County, Iowa 115 
The Grasses of the Uintah Mountains and Adjacent Regions 133 
The Diclinous Flowers of Iva Ganthifolia ...... . 151 
Phylogeny of the Araceae 161 
•The Effect of Smoke and Gases Upon Vegetation 169 
Nitrogen in Rain and Snow 189 
The Rock from Solomon’s Quarries......... 193 
Segregation of Fat Factors in Milk Production. 195 
Complete Succession of Iowan Cretacic Terranes 199 
Recognition of Beds of Tertiaric Age in Our State 203 
Late Devonic Sequence of The Iowa Region 205 
The Proper Use of the Geological Name “Bethany” 207 
A Pleistocene Section from Des Moines South to Allerton 213 
Preliminary. Note on the So-called “Loess” of Southwestern Iowa 221 
Notes on the Nebraskan Drift of the Little Sioux Valley in Cherokee County 231 
The Wisconsin Drift Plain in the Region about Sioux Falls 237 
Additional Evidences of Post-Kansan Glaciation in Johnson County, Iowa. 251 
Mounds and Mound Explorations in Northeastern Iowa 257 
The Similarity of Electrical Properties in Light-Positive Selenium to 
Those in Certain Crystal Contacts 261 
A Practical Electrical Method of Measuring the Distances Between Parallel 
Conducting Planes, with Application to the Question of the Existence 
of Electron Atmospheres 271 
The Use of the Rayleigh Disk in the Determination of Relative Sound 
Intensities 279 
An Experimental Investigation of tlite Relation Between the Aperture of 
a Telescope and the Quality of the Image Obtained by it 283 
On the Existence of a Minimum Volume in Solution 289 
On Certain Points in the Anatomy of Siren Lacertina 291 
Helpful and Harmful Iowa Birds 295 
A Further Study of the Home Life of the Brown Thrasher 299 
Nest Boxes for Woodpeckers 305 
Food Habits of the Skunk 307 
Additional Mammal Notes 311 
Life History Notes on the Plum Curculio in Iowa 313 
Color Inheritance in the Horpe 317 
Some Factors Affecting Fetal Development 325 
A Case of Urticaria Factitia Observed in the Coe College Psychological 
Laboratory 331 
