1. There is no demonstrable amount of agglutinin for Treponema pallidum (Noguchi) in normal human and normal rabbit serum in dilutions as low as 1:20.
2. Agglutinins for Treponema pallidum are readily produced in young rabbits by the administration of pure cultures of living spirochetes.
3. There is no appreciable amount of agglutinin for Treponema pallidum culture used in the sera of secondary and tertiary syphilis or in the cerebrospinal fluid of tertiary syphilis in dilutions of 1:20 to 1:640.