CONTENTS 



CHAPTER I 

 INTRODUCTION 



Immunology 19 



Infection and Infectious Diseases 20 



CHAPTER II 

 THE NATURE OF INFECTION 



Local Conditions and Infection 22 



Obstacles to Infection 24 



CHAPTER III 

 THE OFFENSIVE FORCES OF THE INVADING MICROORGANISM 



Classification of Microparasites 28 



Virulence and Aggressivity 31 



Aggressins 33 



Passive Aggressivity 34 



Active Aggressivity 38 



CHAPTER IV 



BACTERIAL POISONS 



Ptomains 45 



Toxins 46 



Endotoxins 49 



Bacterial Proteins 49 



Infection with Animal Parasites 52 



CHAPTER V 



THE DEFENSIVE FORCES OF THE MACROORGANISM 



Phagocytosis 54 



The Opsonins and Bacteriotropins ... .... 58 



Chemotaxis 62 



