CONTENTS 



EXEBCISE PAGE 



1 . How Plants Grow 1 



2. Where The Plant Obtains its First Food 3 



3. To Show That Plants Get Food Material from the Soil 5 



4. To Show How Plants Take up Food Material from the Soil . . 8 



5. To Show That Sunhght is Necessary for Plant Growth 10 



0. To Show That Air is Necessary for the Germination of Seeds 



and the Growth of Plants 12 



7. To Show That Heat is Necessary for Plant Growth 14 



8. To Show That Plants Take up Moisture from the Soil and 



Give it off Through their Leaves 16 



9. To Show the Am»ount of Moisture Retained by Plants 18 



10. To Study the Growth Rate of Plants 20 



11. To Show the Proper Depth for Planting 22 



12. A Study of Corn r4 



13. The Corn Kernel 20 



14. The Study of an Ear of Corn 119 



15. Early Growth of the Corn Plant 31 



16. A Study of the Mature Corn Plant ?3 



17. PoUination of Plants 26 



18. The Selection of Seed Corn in the Field 39 



19. The Storage of Seed Corn 42 



20. Judging Corn Ears 46 



21. To Study the Effect of Stand upon the Yield of Corn 51 



22. To Test the Vitahty of Seed Corn 53 



23. Testing the Corn Planter 57 



24. To Study the Necessity for Proper Cultural Methods foi ( om. 59 



25. The Production of Corn in the United States G2 



26. Study of a Head of Wheat 65 



27. Early Development of the Wheat Plant 68 



28. Judging Wheat 70 



29. The Production of "Wheat in the United State.i 72 



vii 



