CONTENTS 



CHAPTER I 

 INTRODUCTION 



Immunology 19 



Infection and Infectious Diseases 20 



CHAPTER II 

 THE NATURE OF INFECTION 



Local Conditions and Infection 23 



Obstacles to Infection 25 



CHAPTER III 



THE OFFENSIVE FORCES OF THE INVADING MICROORGANISM 



Classification of Microparasites 



Virulence and Aggressivity 32 



Aggressins 35 



Passive Aggressivity 35 



Active Aggressivity 41 



CHAPTER IV 



BACTERIAL POISONS 



Ptomains 48 



Toxins 49 



Endotoxins 52 



Bacterial Proteins .52 



Infection with Animal Parasites .... 55 



CHAPTER V 



THE DEFENSIVE FORCES OF THE MICROORGANISM 



Phagocytosis 57 



The Opsonins and Bacteriotropins .61 



Chemotaxis 65 



