Local immunity, or a better term, resistance to reinoculation in syphilis has been established as a fact both experimentally and clinically. Information is lacking with regard to the behavior ofSpirochaeta pallidawhich have been exposed to such influences as might logically be assumed to modify the course of an infection in the animal body. It has been shown in a previous study1that syphilis in man, when latent and outwardly inactive, can be associated with the presence ofSpirochaeta pallidain the glands and in the semen. In the experimental animal this question has been approached as a control on the problem in man, and results, such as localization in certain glands and preliminary observations bearing on latency in experimental syphilis, have been recorded in another place.2The brilliant studies of Brown and Pearce3which were made in connection with the therapeutic action of drugs have