CONTENTS 



PART I. BIOLOGY OF THE HIGHER SEED PLANTS 

 SECTION I. PLANTS AND THE ENVIRONMENT 



PAGE 



A. THE BODY PLAN AXD FORM OF PLANTS 3 



The Lilac 3 



Herbaceous Plants 6 



Trees (Spruces and Pines) 9 



Trees (the American Elm) 13 



B. ADJUSTMENT TO THE ENVIRONMENT 18 



The Embryo and Seedling of the Bean 18 



Experiments 20 



Supplementary Studies 21 



SECTION II. CELL STRUCTURE AND GROWTH 



A. THE CELLULAR STRUCTURE OF PLANTS .22 



Cell-Wall Thickening and Cell Differentiation 24 



Protoplasm, Vacuoles, and Nuclei in Root-Tip Cells ... 26 

 Cell Structure and Protoplasmic Streaming in Stamen Hairs 



of Tradexcantia t .27 



Plastids in Plant Cells 30 



B. CELL STRUCTURE AND GROWTH 31 



Growth 31 



C. THE CELL AND CELL DIVISION 35 



Supplementary Studies 39 



