Estimation of the dose of antigen required to produce antibodies upon injection into the carotid sinus

The minimal quantity of microbic bodies capable of causing antibody production when in contact with receptors of isolated carotid sinus was determined. It was demonstrated that this antigenic dose is not connected with increase of the titer of specific agglutinins, when injected intravenously to dogs of the same weight. This is an additional confirmation of the possibility of the reflex mechanism of antibody production.