2. This form of active immunity may be induced by the injection of S or R strains of Pneumococcus.

3. Intracutaneous immunization with soluble derivatives of Pneumococcus does not induce active immunity to infection.

4. The sera of seventy-nine per cent of the rabbits immunized to Type I Pneumococcus by intracutaneous injections afforded no protection to mice against infection with pneumococci.

5. None of the sera of rabbits intracutaneously immunized to the type-specific Type III (S) pneumococci, to R cells, or to soluble derivatives of Pneumococcus protected white mice against infection.

6. The sera of rabbits immunized first intracutaneously and subsequently intravenously possess a high titre of protective antibodies.

7. It may be concluded that when type-specific pneumococci are injected into the skin they lose the property of stimulating an active immunity of a specific type and of stimulating the production of type-specific antibodies, but they act just as do the degraded or R forms, causing the animals to become resistant to infection with pneumococci of all types without the development of any type-specific antibodies in the serum.