TABLE OF CONTENTS 



(Numbers in the text refer to paragraphs.) 



CHAPTER I PAGES 



HORTICULTURE AND PLANT IMPROVEMENT 3-15 



Horticulture denned, 1; Plant material, 2; Va- 

 rieties not permanent, 3; Change is universal, 4; 

 The nightshade family, 5; The potato, 6; Inter- 

 grafting, 7; Domestication, 8; American wild plants, 

 9. The Process of Improvement: Darwin, 10; The 

 origin of species, 11; Mendel, 12; Mendel's law, 13; 

 Dominant and recessive characters, 14; De Vries, 

 15; The mutation theory, 16; Plant improvement 

 a division of science, 17; Hybridization, 18; One 

 effect of hybridization, 19; Bud-selection, 20; Ways 

 in which plants vary, 21; Life forms not fixed, 22; 

 Modern conditions demand the best, 23; The goal, 

 24. 



CHAPTER II 



THE LIVING PLANT 16-38 



Parts of plants, 25; The cell, 26; Number of cells 

 necessary to plant life, 27; Structure of plant-cells, 

 28; The cell-wall, 29; The ectoplasm, 30; Pro- 

 toplasm, 31; The nucleus, 32; Cytoplasm, 33; 

 Vacuoles, 34; Plastids, 35; Functions of plant parts, 

 36; Roots, 37; Manner of growth of roots, 38; 

 Functions of roots, 39; The stem, 40; Structure and 

 functions of the stem, 41; Growth of stems, 42; 

 Buds, 43; Fruit-buds, 44; The leaves, 45; Structure 

 of leaves, 46; The functions of leaves, 47. 



CHAPTER III 



PROPAGATION BY SEEDS 39-53 



Sexual reproduction, 48; Structure of the seed, 49; 



The pea, 50; The bean, 51; The pumpkin seed, 52; 



The corn, 53; Two classes of plants, 54; How plants 



come up, 55; Seed dissemination, 56; Rest-period of 



xi 



