The Treponema pallidum haemagglutination (TPHA) test, the latest to be developed in the group of specific tests for syphilis, has been described by Tomizawa and Kasamatsu (1966), Rathlev (1967), Tomizawa, Kasamatsu, and Yamaya (1969), and Tringali (1970.) An automated microhaemagglutination technique, the AMHA-Tp test, has been evaluated by Cox, Logan, and Norins (1969) and Logan and Cox (1970)...