Reaction of Rabbits to Streptococci: Comparative Sensitizing Effect of Intracutaneous and Intravenous Inocula in Minute Doses

1. Rabbits were rendered very hypersensitive by relatively small doses of green streptococci given intracutaneously, and somewhat less hypersensitive by similar doses of heat-killed vaccine prepared from hemolytic streptococci. 2. Animals receiving the same doses intravenously gave, upon subsequent testing, lesions slightly more marked than normal controls; but these lesions were qualitatively hard and nodular compared with the large edematous lesions in the cutaneously sensitized group. 3. There was no parallelism between the degree of cutaneous or ophthalmic hypersensitivity and agglutinin titer in the blood serum. 4. Bacterial hypersensitivity to whole streptococci appears to depend more upon previously induced focal infection than upon circulating antibodies.