CONTENTS 



CHAPTER PAGE 



1. The Biology of To-morrow 1 



II. The Growth of Science 10 



III. The Microscope 19 



IV. The History of Cells 27 



V. Functions of a Green Cell 34 



VI. Typical Animal Cell 42 



VII. The Resting and Dividing Cell 53 



VI 11. Structure of Higher Plants 66 



IX. Human Tissues 73 



X. Human Tissues {Continued) 83 



XL Food Nutrients 91 



I/' XII. The Teeth and Their Care 107 



A XIII. The Digestive System 114 



XIV. Digestion and Absorption . . ; . . . .125 



XV. Blood and Its Importance 143 



XVI. Circulatory System 151 



XVII. Lymphatic System 163 



XVIII. The Skin and Kidneys 170 



XIX. Respiration . . . 177 



— *XX. Metabolism . . .187 



XXI. Ductless Glands . . " 191 



XXII. The Nervous System 202 



XXIII. Nervous Reactions 215 



XXIV. Mental Hygiene 227 



XXV. How Life Began 239 



XXVI. Asexual Reproduction r . 246 



vii 



