CONTENTS 



PAGE 



INTRODUCTION . . < i 



CHAPTER 



I. LIVING AND LIFELESS MATTER 6 



1 . The Chemical Composition 7 



2. Metabolism or the Power of Waste and Repair .... 9 



3. Growth by Intussusception 12 



4. Reproduction 13 



5. Power of Adaptation 15 



II. PROTOPLASM AND THE CELL, AND ORGANISMS OF ONE CELL. . . 26 



A. The Organization and Vitality of Yeast Cells 29 



B. Bacteria 34 



C. Enzymes, Hormones and Vitamines 37 



III. ORGANISMS OF ONE CELL, Continued 44 



A. Amoeba proteus 44 



B. Flagellated Protozoa, Chilomonas and Allied Forms . . 53 



C. A Ciliated Protozoon, Paramecium caudatum 60 



D. Biological Problems associated with Protozoa .... 65 



IV. ORGANISMS OF TISSUES 76 



A. Hydra fusca and Hydra viridis 82 



Histology 83 



Physiology 90 



Symbiosis 96 



Polymorphism 98 



B. Summary 100 



V. PLANTS, THE FOOD OF ANIMALS AND THE SOURCES OF ANIMAL 



ENERGY 103 



A. The Food of Animals 103 



B. Pleurococcus pluviatilis and Sphaerella lacustris. . . 106 



C. Pteridium aquilinum no 



Histology 112 



General physiology 118 



Reproduction * 22 



VI. ORGANS AND ORGAN SYSTEMS 13 



I. General 130 



II. Structures and Functions of the Earthworm, Lumbri- 



cus sp T 3 J 



A. Habits and Mode of Life i3 2 



B. Regional Differentiation 133 



C. Internal Structure I3 6 



vii 





