X 
IOWA ACADEMY OF SCIENCE 
TABLE OF CONTENTS 
Page 
Letter of Transmittal HI 
Officers of the Academy V 
Members VI 
Table of Contents X 
Report of the Secretary 1 
Report of Committee on the Metric System 2 
Report of Committee on the Death of Lord Kelvin 5 
Report of Committee on Life Membership and Prizes. 6 
Reports of General Committees . 6 
Treasurer’s Report 7 
Necrology. Charles Aldrich 10 
President’s Address 13 
The Solar Surface During the Past Five years 17 
The Viability of Weed Seed Under Different Conditions of Treatment 25 
Notes on the Histological Structure and Specific Gravity of the Seeds 
of Pyrus 47 
The Genesis of Loess: A Problem in Plant Ecology 57 
A Hybrid Oak 77 
Notes on Peronosporales for 1907 85 
Some Forestry Problems of the Prairies of the Middle West.... 91 
A Case of the Isolation of Diphtheria Bacilli from a Post Mortem (Abst.) 97 
The Uric Acid Ferments 99 
The. Determination of Ferrous Iron 105 
The Decomposition of Dolomite 107 
Some Iowa Waters 109 
The Life of Portland Cement Ill 
The Loess of the Paha and the River Ridge 117 
Eolian Origin of Certain Lake Basins of the Mexican Table Land 137 
Stratigraphic Position of Western Red-Beds 143 
Some Relations of the Older and Younger Tectonics of the Great Basin 
Region (Abstract) ' 145 
Some Peculiarities in the Elastic Properties of Certain Substances 147 
Determination of the Charge of an Electron by Wilson’s Method, Using 
Radium 157 
Nucleations According to Barus 165 
Some Protozoans from Fayette, Iowa 169 
A Study in Wing Veination 173 
Protective Adaptations in the Nesting Habits of Some Central American 
Birds 177 
Revival of an Old Method of Brain Dissection 183 
Index .* 189 
