Small areas of skin infiltrated with immune serum proved refractory to the injurious action of a filterable rabbit virus inoculated 24 to 48 hours later. Infiltrations of normal serum did not appreciably protect the skin against the virus. The local protection afforded by the infiltrations of immune serum appears to constitute an example of local passive immunity.
Small areas of skin infiltrated with either normal serum or meat infusion broth proved more refractory than normal skin to infection with hemolytic streptococci inoculated 24 hours later. The refractory state induced in the tissues was non-specific in character. A greater amount of local protection against hemolytic streptococci was afforded by infiltrations with a homologous immune serum than by infiltrations with normal serum. The difference in the amount of protection afforded by immune serum over that induced by normal serum may be thought of as representative of the degree of local passive immunity conferred.