CONTENTS 



PART I. THE STRUCTURE AND FUNCTIONS OF 

 ORGANISMS THE CELL THEORY 



CHAPTER I 



PAGE 



Introductory : The nature of life The living organism viewed as a 

 machine The essential functions of the living body The source 

 of energy in living things 1 



CHAPTER II 



Amoeba as a typical organism The properties of protoplasm . . 12 



CHAPTER III 

 Hsematococcus The differences between animals and plants . . 27 



CHAPTER IV 



The cell theory Unicellular organisms Differentiation and division 

 of labour Co-operation The transition from the unicellular to 

 the multicellular condition The early development of multicellular 

 animals and plants .......... 36 



CHAPTER V 



The cell theory as illustrated by the histological structure of the higher 

 animals and plants Limitations of the cell theory The cell as 

 the physiological unit 51 



CHAPTEE VI 

 The multiplication of cells Mitotic and amitdtic nuclear division . 69 



PART II. THE EVOLUTION OF SEX 



CHAPTER VII 



Limitation of the powers of cell-division Rejuvenescence by conjuga- 

 tion of gametes The origin of sex in the Protista . . .81 



