ILLUSTRATIONS 



FIG. PAGE 



Wheat, the Staff of Life, as Grown in the Great Plains of Nebraska 

 . Frontispiece 



1. The Agricultural Regions of the United States 



la.Diagram Illustrating the Relative Proportion of Dry Matter and 



Water in a Green Plant 6 



2. Root-hairs 8 



3. Diagram Illustrating the Assimilation of Food Materials by a Plant . 10 



4. Germination in Corn 15 



5. Wheat Grain in Three Stages of Germination, on the First, Second, 



and Third Days after Being Placed in Germinator 16 



6. Germinator Made by Inverting a Glass Tumbler on a Glass Plate; 



Also One Made with Two Plates and Blotting Paper 18 



7. A Box Germinator 19 



8. Germinating Oats and Barley 21 



9. Early Development of Wheat Plant 22 



10. Comparative Study of Spikelets 24 



11. Diagram of a Wheat Flower 25 



12. Ovary of Wheat Grain 25 



13. Diagram of a Corn Kernel to Show the Four Principal Parts 26 



14. Plowing Under Rye for Green Manure 33 



15. Distribution of Corn Production in the United States 42 



16. Coyote Corn, a Form Found Growing W T ild in Mexico 44 



17. Six Principal Types of Corn 45 



18. Kernels of Principal Types of Corn 46 



19. Ears of Corn in Full Silk, and Ready to be Fertilized 50 



20. Method of Preparing a Laboratory Exercise, and also Showing in 



Detail the Male and Female Flowers of Corn 51 



21. Corn Plant Prepared for Artificial Crossing 52 



22. Effect of Crossing and Self-Fertilization on Vigor of Plants 53 



23. Stalk of Prolific Corn, Leaves Removed to Show Ears 59 



24. Difference in Types of Corn 60 



25. Two Types of Learning Corn Developed by Six Years' Selection at 



the Illinois Experiment Station 61 



26. A Box Tester for Seed Corn 63 



27. Wheat Plant Illustrating the Principle that Permanent Roots 



Always Develop at About the Same Depth, Whether the Seed Is 



Planted Deep or Shallow 70 



28. Two-row Cultivator, for Listed Corn, at Work 75 



29. Drawing Showing the Distribution of Corn Roots in the Soil 78 



29a.Corn Cut for Forage or Fodder 



30. Corn Sold or to be Sold 



30a. Harvesting Corn by Hand . 81 



31. Harvesting Corn with a Corn Binder 82 



Sla.Crops Cut for Silage, Acreage 1919 



32. An Ideal Ear of Dent Corn of Fancy Type 96 



33. Shape of Ear 97 



34. Tips of Ears 100 



35. Butts of Ears 100 



XV 



