STUDIES ON IMMUNITY TO PNEUMOCOCCUS MUCOSUS (TYPE III) : I. ANTIBODY RESPONSE OF RABBITS IMMUNIZED WITH TYPE III PNEUMOCOCCUS.

1. Type III pneumococci fail in the majority of instances to stimulate the production of anti-S antibodies. (Type specific agglutinins, type specific precipitins, and antibodies affording type specific protection in mice.) 2. Type III pneumococci are effective in the stimulation of the production of anti-P antibodies (agglutinins for R strains of pneumococci and precipitins for pneumococcus nucleoprotein). These antibodies are ineffectual in the passive protection of mice.