A method for the direct cultivation of Treponema pallidum from human syphilitic lesions, by the employment of a solid medium, has been described. By means of it, three of the four strains worked with were successfully cultivated.
The several pure cultures agree in morphological and cultural characters, grow only in the presence of sterile tissue under anaerobic conditions, and do not produce putrefactive odors. The morphology is typical under optimum cultural conditions; it becomes atypical when the conditions are unfavorable.
In cultures, Treponema pallidum multiplies by longitudinal division. The process is usually symmetrical but occasionally appears to be asymmetrical.
Inoculation of the pure cultures into the skin of two species of lower monkeys was followed by the production of lesions resembling the primary syphilitic lesion occurring in man and those caused in the monkey by inoculation of spirochætæ-containing serum from human sources.
During the course of the positive inoculation in the monkey, the blood develops the property of giving a positive Wassermann reaction. Thus the relation of Treponema pallidum to this reaction is supported, and the identity of the cultivated strains with the species found in human syphilitic lesions established.