TABLE OF CONTENTS Xlll 



PAGE 



The action of chemicals on bacteria 140 



P'ormaldehyde, etc 148 



CHAPTER XIII 

 THE RELATION OF BACTERIA TO ENVIRONMENT (Continued} 



THE EFFECT OF EXTERNAL CONDITIONS 



Light 155 



Electricity 159 



Rontgen rays 162 



Movement ........... 163 



Pressure 163 



Association 164 



CHAPTER XIV 

 THE METABOLISM OF BACTERIA 



Introduction 165 



The general character of life processes 165 



Anabolism 166 



Catabolism 167 



Respiration 168 



CHAPTER XV 

 THE PRODUCTS OF THE METABOLISM OF BACTERIA 



Introduction 171 



Bacterial enzymes and their mechanism of action . . . .176 

 Autolytic bacterial enzymes 181 



PART VI. THE BIOLOGY OF SPECIALIZED 

 GROUPS OF BACTERIA 



CHAPTER XVI 

 THE PROTOTROPHIC BACTERIA 



Introduction * 183 



Nitrifying bacteria . . . .183 



Nitrogen-fixing bacteria 185 



