Contents xiii 



CHAPTER VII 



PAGE 



The mechanism of natural immunity against micro-organisms . .175 

 The destruction of micro-organisms in natural immunity is an act of re- 

 sorption. — Part played by inflammation in natural immunity. — Importance 

 of microphages in immunity against micro-organisms. — Chemiotaxis of 

 leucocytes and ingestion of micro-organisms. — Phagocytes are capable 

 of ingesting living and virulent micro-organisms. — The digestion of micro- 

 organisms in phagocytes is most often effected in a feebly acid medium. — 

 Bactericidal property of serums. — Phagocytic origin of the bactericidal 

 substance. — Theory of the secretion of the bactericidal substance by 

 leucocytes. — Comparison of the bactericidal power of serums and of 

 blood plasmas. — The bactericidal substance of blood serums must not 

 be considered a secretion-product of leucocytes ; it remains within the 

 phagocytes, so long as they are intact. — The cytases. — Two kinds of 

 cytases : macrocytase and microcytase. — Cytases are endo-enzymes, allied 

 to trypsins. — Changes in the staining properties and in the form of micro- 

 organisms in the phagocytes. — Absence or rarity of fixatives in the 

 serums of animals endowed with natural immunity. — The agglutination 

 of micro-organisms does not play any important part in the mechanism 

 of natural immunity. — Absence of antitoxic property of the body fluids 

 in natural immunity. — The phagocytes destroy the micro-organisms 

 without their ingestion being preceded by neutralisation of the toxins. 



CHAPTER YIII 



Survey of the facts bearing on acquired immunity against micro- 

 organisms 207 



The discovery of attenuated viruses and its application to vaccination against 

 infective diseases. — Vaccination by microbial products. — Vaccination with 

 serums. — The acquired immunity of the frog against pyocyanic disease. 

 — The acquired immunity against vibrios. — Extracellular destruction of 

 the cholera vibrio. — Part played by two substances in Pfeiflfer's pheno- 

 menon. — Specificity of fixatives. — Phagolysis and its relation to the extra- 

 cellular destruction of vibrios. — Part played by phagocytosis in the 

 acquired immunity against vibrios. — Fate of the spirilla of recurrent 

 fever in the organism of immunised guinea-pigs. — Acquired immunity 

 against the bacteria of typhoid fever and pyocyanic disease. — Acquired 

 immunity against swine erysipelas and anthrax. — Acquired immunity 

 against the streptococcus. — The acquired immunity of rats against 

 Trypanosoma. 



CHAPTER IX 



The mechanism of acquired immunity against micro-organisms . . 250 



Cytases and fixatives. — Only the latter are augmented in the immunised 

 organism. — Properties of the fixatives. — Di£ference between them and 

 the agglutinative substances. — The part played by the latter in acquired 

 immunity. — Protective property of the fluids of the immunised organism. 

 — Stimulant action of the body fluids. — The protective power of serum 

 cannot serve as a measure of acquired immunity. — Examples of acquired 

 immunity in which the serums exhibit no protective power. — Phago- 



