CONTENTS 



PAGE 



I. The Origin of Life .... 3 



II. Growth 8 



III. Reproduction 22 



IV. Motion 29 



V. Irritability 34 



VI. Metabolism 45 



VII. Selective Permeability ... 74 



VIII. Electrical Forces 84 



IX. The Control of Life .... 88 



Index Ill 



vu 



