Rapidity With Which Spirochaeta Pallida Invades the Blood Stream

The question of the rapidity with which Spirochaeta pallida invades the blood stream and the lymph nodes after syphilitic inoculation possesses considerable theoretical and practical importance. The conception of the course of the syphilitic infection, especially in its early stages, has been entirely changed as the result of the discovery that lymph nodes and blood of infected animals may contain spirochetes long before any observable manifestations of syphilis appear. Uhlenhuth and Mulzer1showed as early as 1910 that the lymph nodes of rabbits inoculated intratesticularly are enlarged and contain spirochetes as demonstrated by dark field examination at the time lesions appear in the testicles. The rapidity with which Spirochaeta pallida reaches the lymph nodes from the initial focus of infection has been studied extensively by Brown and Pearce.2They obtained positive results by infecting normal animals intratesticularly with an emulsion of lymph nodes of rabbits excised forty-eight