STUDIES ON FERMENT ACTION : V. IMMUNIZATION WITH PROTEOLYTIC CLEAVAGE PRODUCTS OF PNEUMOCOCCI.

1. Leucoprotease splits pneumococci into lower cleavage products than are obtained with the autolytic ferment contained in the pneumococci. 2. Such cleavage products injected into rabbits have the property of producing immune bodies in the blood of the injected animals. 3. These experiments indicate that proteolysis plays a part in the production of pneumococcus immunity.