THE MORPHOLOGY OF TREPONEMA PALLIDUM IN THE ELECTRON MICROSCOPE: DEMONSTRATION OF FLAGELLA

In a recent issue ofThe Journalwe published a short note on the appearance of Treponema pallidum when seen under the electron microscope.1All the preparations were specimens recovered directly from human material, for the most part primary and secondary lesions. When the preparations were examined in the electron microscope we were unable to discern flagella despite all the evidence which points to their presence when visualized in the living state by darkfield illumination. In a footnote in our original contribution we stated that flagella-like processes were demonstrable by careful inspection of the photographic plate. This apparent difference between what can be seen on the fluorescent screen of the microscope and what is evident on the photographic plate is due to the lesser resolving power of the fluorescent screen. In the investigation of bacteria, including Treponema pallidum, with the electron microscope, a magnification of approximately 9,000 diameters has