TABLE OP CONTENTS. 
Page 
Letter of Transmittal ill 
Table of fJontents ...... v 
Officers of the Academy vi 
Membership of the Academy. ......... vii 
Necrology—Mrs. N. E. Hansen ...... xi 
Proceedings of the Nineteenth Annual Session xiii 
Presidential Address, by B. Shimek. ... 1 
Apparatus for Plating out Petri Dishes in the Field, by L . S. Ross ... 7 
A Method for the Determination of Hydriodic and Hydrobromic Acids, by W. S. 
Hendrixson 9 
Notes on American Cladonias, by Bruce Pink 15 
Some Notes on Certain Iowa Algse, by Bruce Fink 21 
Cohesion of Water and of Alcohol, by Edwin Morrison 29 
The Slime Moulds of New Mexico, by T. H. Macbride 33 
An Ecological Study of the Sabine and Neehes Valleys, Texas, by James E. Gow. 39 
J. J. Thomson’s Theory of Matter, by L. Begeman 49 
Variation in Ray Flowers of Anthemis Cotula and other Composites, by H. S, 
Fawcett 6S 
Notes on a Thermophilic Bacillus, by R. Earl Buchanan 69 
Municipal Hygiene, Parti, by C. O. Bates 76 
Notes on the Flora, especially the Forest Flora, of the Bitter Root Mountains, by L. 
H. Pammel 87 
Methods for the Estimation of Carbon Dioxide in Minerals and Rooks, by Nicholas 
Knight 101 
An Annotated List of Iowa Discomycetes, by Fred Jay Seaver 105 
The Biology of Bacillus Violaceous Laurentius or Pseudomonas Janthina, by Grace 
Roodde Rueda 121 
Plants New to the Flora of Decatur County, Iowa, by J. P. Anderson 133 
The Switchboard and Arrangement of Storage Battery at Simpson College, by John L. 
Tilton .... 189 
Problem in Municipal Waterworks for a Small City, by John L. Tilton 148 
Some Railroad Water Supplies, by L. H. Pammel and Estelle D. Pogel 151 
Flowering Plants of Henry County, by J. M. Lindly 167 
Bisection of Mountain Blocks in the Great Basin Region, by Charles R. Keyes 165 
Geological Structure of the Jornada Del Muerto and Adjoining Bolson Plains, by 
Charles R. Keyes 167 
Northward Extension of the Lake Valley Limestone, by Charles R. Keyes. 169 
Growth and Pigment Production of Pseudomonas Janthina, by Harry P. Watt 173 
*The Synthesis of Ethyl Alcohol from Acetylene, by J. C. Prazee 179 
A List of the Flowering Plants of Hardin County, Iowa, by Morton E. Peck 193 
Index 243 
* This paper was omitted from volume XI on account of lack of space. 
