Abstract
The ultra-thin sections of My. ulcerans were examined with electron microscope.
1) Two types of bacillary bodies, namely, the homogenous, solid type and the type which has various internal structures were observed. The many intermediate forms between both variations were observed and they could be divided decidedly.
2) The bacillary body is enveloped with a cell wall. Within the bacillary body, large electron-dense granules (50-100mu), small granules (about 20mu), electron-transparent vacuolous structures, and reticular, tubular and ramifying string-like structures were recognized.
3) The internal structure of My, ulcerans is very similar to those of murine, human leprosy bacilli, and tubercle bacilli.
