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.—Difference
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.—Phagocytosis in acquired
immunity.—Negative chemiotaxis of leucocytes.—Theory of
attenuation of micro-organisms by the fluids of immunised
animals.—Refutation of this theory.—Phagocytosis acts without
requiring any previous neutralisation of the toxins.—The origin
of the fixative and protective properties of the body
fluids.—The relation between these properties and
phagocytosis.—The side-chain theory of Ehrlich and the theory of
phagocytes.