xii CONTENTS 



PAGE 



p. 29; Oats, p. 29; Other Self-Fertilized Plants, p. 30; Pota- 

 toes, p. 30; How Often Do Potatoes Need to Be Grown from 

 the Seed-Ball, p. 30; Plant-Breeding Farms, p. 31. 



Questions 31 



Laboratory Exercises 32 



Collateral Reading 34 



CHAPTER III 

 PROPAGATION OF PLANTS 36-59 



Methods of Propagation 36 



Spores, p. 36; Creeping Stems and Rootstocks, p. 36; Roots, 

 p. 39; Tubers, p. 39; Cuttings, p. 41. 



Grafting 42 



Budding, p. 43; Root-Grafting, p. 45; Top-Grafting, p. 46; 

 Relationship of Cion and Root, p. 47; Effect of Root on Cion, 

 p. 47. 



Seeds 47 



Nature of Seeds, p. 47; Importance of Vigorous Germina- 

 tion, p. 48; Germination Tests of Seed Corn, p. 48; Seed 

 Analysis and Valuation, p. 51; Germination Tests, p. 51; 

 Purity and Germination Tests, p. 52; What is the Cheapest 

 Seed, p. 52; Size and Weight of Seeds, p. 53; Seed-Testing 

 Is Plant-Selection, p. 54; Storage of Seed, p, 54; Importation 

 of Low-Grade Seed, p. 55. 



Questions 55 



Laboratory Exercises 56 



Collateral Reading 59 



CHAPTER IV 

 PLANT FOOD 60-74 



Elements Required for Plant and Animal Growth, p. 60; Sources 

 of Plant Food, p. 61; Water, Dry Matter and Ash, p. 62; 

 Relative Amounts of the Different Elements in Plants, 

 p. 62; Elements Likely to Be Deficient in Soils, p. 63; Func- 

 tions of the Different Elements, p. 63. 



