If the bacillus, discovered in 1884 by Lustgarten,” in Weigert's laboratory, is really the specific virus of syphilis, this bacillus undoubtedly belongs to the general acrodynamic bacteria, though giving rise to a remarkably slow dynamic evolution of the organisms, this latter remaining unusually long in the different states that correspond to the different degrees of the dynamic evolution of syphilis.
Source: wiktionary