By a method of cultivation that proved successful with Bacterium pneumosintes, characteristic surface colonies of old saprophytic strains of Treponema pallidum and Treponema calligyrum have been obtained. The presence of two types of colony in the pallidum cultures requires explanation, but the fact of colony formation may point the way to new methods of isolation and identification and to the utilization of suspensions of treponemata, free from foreign proteins, for serological and immunological purposes.

This content is only available as a PDF.