CONTENTS 
Page 
Summary 4 
Object and Scope of tbe Investigations 9 
The Environmental Survey of Nebraska’s Corn Growing Conditions. . .11 
Climate 12 
Regional Temperature Variations Within the State 13 
Normal Mean Temperature 13 
Normal Length of Frost-Free Growing Season 14 
Regional Moisture Variations Within the State 14 
Mean Annual Precipitation . 15 
Evaporation Rate 15 
Absorptive and Retentive Power of the Soil 18 
Soil Fertility 19 
Summary of Conditions When Corn Types Were Studied 19 
Normal Regional Differences 19 
Temperature and Rainfall During 1915 and 1916 20 
The Corn Types Survey of Nebraska 21 
Two Classes of Investigations 21 
Native Com Types Grown at Home 22 
Morphological Characters 22 
Methods of Study 22 
Results 22 
Histological Characters 23 
Methods of Study 23 
Results 29 
Native Corn Types Grown Out of Their Home Evironment 37 
Morphological Characters 38 
Histological Characters 48 
Comparative Yield of Native Types 57 
Comparative Transpiration of Eastern and Western Corn Types 60 
Comparative Yields of Corn From Various Sources in Eastern Nebraska. .61 
Local Corn Compared With Corn From Other States 64 
