CONTENTS 



CHAP. PAQB 



INTRODUCTION ix 



I. THE ORIGIN OF LIFE 11 



II. THE CRITERIA OF LIFE ..... 14 



in. THE CELL 16 



IV. CELL-DIVISION 21 



V. DIFFERENTIATION OF STRUCTURE AND DIVI- 

 SION OF LABOUR 23 



VI. SENSITIVITY IN PLANTS AND ANIMALS . 33 

 VH. RESPONSE TO CERTAIN STIMULI IN PLANTS AND 



ANIMALS 37 



VIII. MOTION AND LOCOMOTION .... 42 



IX. FOOD 46 



X. REPRODUCTION 54 



XI. ONTOGENY ....... 58 



XII. THE ADAPTATION OF ORGANISMS TO THEIR 



ENVIRONMENT ...... 65 



XIII. THE STRUGGLE FOR EXISTENCE ... 74 



XIV. THE PAST HISTORY OF LIVING ORGANISMS . 78 

 XV. HEREDITY 80 



XVI. OLD AGE AND DEATH 84 



BIBLIOGRAPHY 89 



INDEX . 91 



vii 



