xvi Contents 



CHAPTER XV 



PAOR 



Protective vacoinations 454 



Vaccinations against, I. Small-pox. — II. Sheep-pox. — III. Rabies.— IV. Rinder- 

 pest. — ^V. Anthrax. — ^VI. Symptomatic Anthrax. — VII. Swine Erysipelas. 

 — VIII. Pleuropneumonia in the Bovidae. — IX. Typhoid Fever. — 

 X. Plague.— XI. Tetanus.— XII. Diphtheria. 



CHAPTER XVI 



Historical sketch op our knowledge of immunity 505 



Methods used by savage races for vaccination against snake venom and against 

 bovine pleuropneumonia. — ^Variolisation and vaccination against small- 

 pox. — Discovery of the attenuation of viruses and of vaccinations with 

 attenuated micro-organisms. — Theory of the exhaustion of the medium as 

 a cause of acquired immunity. — Theory of substances which prevent the 

 multiplication of the micro-organisms in the refractory body. — Local 

 theory of immunity. — Theory of the adaptation of the cells of the im- 

 munised organism. 



Observations on the presence of micro-organisms in the white corpuscles. — 

 History of phagocytosis and of the theory of phagocytes. — Numerous 

 attacks upon this theory. — Theory of the bactericidal property of the 

 body fluids. — Theory of the antitoxic power of the body fluids. — Extra- 

 cellular destruction of micro-organisms. — Analogy between bacteriolysis 

 and haemolysis. — Theory of side-chains. 



Progress of the theory of phagocytes. — Attempts to reconcile it with the 

 humoral theory. — Present phase of the question of immunity. 



CHAPTER XVII 

 Summary 544 



Means of defence of the animal against infective agents. — Absorption of micro- 

 organisms. — Phagocytes, and their function in inflammation. — The action 

 of phagocytes in the absorption of micro-organisms. — The cytases, phago- 

 cytic ferments. — The cytases are closely bound up with the phagocytes. — 

 The fixatives and their function in acquired immunity. — The fixatives are 

 excreted by the phagocytes and pass readily into the fluids of the body. 

 — Essential mechanism of the action of the fixatives. — Adaptation of 

 phagocytes to destroy micro-organisms in acquired immunity. — Diff'erence 

 between the fixatives and the agglutinins. — Antitoxins and their analogy 

 with the fixatives. — Hypotheses as to the origin of antitoxins. — Cellular 

 immunity is a fact of general import. — Susceptibility and its role in 

 immunity. — Applications of the theory of immunity to medical practice. 



Index 671 



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