This is the mode of action of the anti-substances in the case of a haemolytic or bacteriolytic serum.
Of these the most important are (a) bacteriolytic or lysogenic action, (b) agglutinative action, and (c) opsonic action.
The first of these, lysogenic or bacteriolytic action, consists in.
It can be shown that in many cases when bacteria are injected the serum of the treated animal has no bacteriolytic effect, and still an immune body is present, which leads to the fixation of complement; in this case bacteriolysis does not occur, because the organism is not susceptible to the action of the complement.