CONTENTS 



CHAPTER I 



PAGE 



THE GENERAL FUNCTIONS OF MICROBES — THE TRANSFORMATION 



CYCLES OF CARBON AND NITROGEN ... . . I 



CHAPTER II 



MICROBES IN THE HUMAN BODY — LIFE WITHOUT MICROBES — 



THE INTESTINAL FLORA ■ ^5 



CHAPTER III 



FORM AND STRUCTURE OF MICROBES SO 



CHAPTER IV 



PHYSIOLOGY OF THE MICROBES . 72 



CHAPTER V 



PATHOGENIC MICROBES — INFECTION I07 



CHAPTER VI 



INFLAMMATION AND PHAGOCYTOSIS ... ... I30 



CHAPTER VII 



THE PATHOGENIC PROTOZOA : FILTER-PASSING VIRUSES . . I4I 



