PAPERS PRESENTED 
13 
Some Notes on Bmpoasca flavescens. R. E. Webster 195 
Simultaneous Fast and Slow Drum Records of Fatigue. F. M. Bald- 
win •• 199 
Notes on Some of the Rarer Birds of the Ames Region. H. E. 
Ewing 211 
Behavior of Trapped and Banded Birds. Dayton Stoner 225 
Morphological Studies on the Injury to Apple Caused by Ceresa 
bubalis. J. C. Goodwin and F. A. Fenton 229 
Nest-digging and Egg-laying Habits of Bell’s Turtle. Frank A. 
Stromsten 229 
Sociology as a Science. Hornell Hart 230 
Chance in Development as a Cause of Variation. P'. W. Whiting. . . . 230 
The Mental and Physical Status of Children Entering the Public 
Schools. J. E. Evans 
Criteria of Superior Intelligence. Reuel H. Sylvester 
Botany 
Some Influences of the Submarginal Vein in Leaves. Robert B. 
Wylie 233 
The Sperms of Vallisneria spiralis. Robert B. Wylie... 
Types of Wound Healing in Certain Foliage Leaves. Robert B. Wylie 238 
Morphology of the Vein-Islet in Certain Dicotyledons. Sara I. Lewis 
Bud Characters of Native Trees of Jasper County. Iowa. F. P. Sipe 
The American Lotus. L. H. Pammel 
The Flora of Yosemite and Adjacent Regions. L. H. Pammel 245 
Further studies on the Germination of Trees and Shrubs. L. H. Pam- 
mel and Miss Charlotte M. King 257 
Notes on Species of Rhamnus of . Southwestern United States and 
California and the Occurrence of Puccinia coronata. L. H. Pammel 267 
The Effects of Weeds Upon Crop Production. A. L. Bakke and L. 
H. Pammel 271 
The Genus Cucurbita — Its Origin, Description and Key to the Species. 
Fred C. Werkenthin... 281 
The Founders of the Art of Plant Breeding. Fred C. Werkenthin 291 
Studies of Insect Transmission and Cross-inoculation of Mosaic on 
the Solanaceae, Cucurbitaceae and Leguminosae. O. H. Elmer 311 
A Comparative Study of the Common and Red-seeded Dandelions. 
Miss June Berry. 313 
A Manual of Ferns and “Fern Allies” of Grinnell and Vicinity. Henry 
S. Conard 317 
A Manual of Gymnosperms (Evergreens) of Iowa. Henry S. Conard 328 
Parry’s Catalog of Iowa Plants of 1848. Miss Winnifred Ellsworth.. 339 
Structure and Function of the Stigma in Relation to the Germinative 
Requirements of the Pollen in the Easter Lily. J. N. Martin, Fred 
C. Werkenthin and Miss Elizabeth Hudson 345 
The Structure and Development of the Seed Coat and Cause of De- 
layed Germination in Mellilotus alba. J. N. Martin 345 
The Relation of the Mosaic Diseases of Wild Catnip and Cultivated 
Cucumbers. J. H. Muncie ’ 346 
Nodal Infection of Corn by Diplodia. L. W. Durrell 346 
