Since Plaut, in 1894, described a spirillum and an associated spindle-shaped bacillus in cases of membranous tonsillitis, and Vincent, in 1896, described similar organisms in cases of hospital gangrene, a large number of observers have reported similar lesions in which the spirillum and the Bacillus fusiformis have been constantly associated.
These lesions have been described as acute, or subacute, ulcerative or membranous inflammations in which were found the characteristic spirilla and bacilli. Morphologically, the fusiform bacilli have been described as spindle-shaped rods with tapering ends, slightly bulging in the center, usually straight, and from 6 to 12 microns in length. The spirilla, usually associated with the bacilli, are delicate spiral-shaped organisms, staining somewhat faintly, and varying considerably in length and in the number of twists or curves. Both organisms take the ordinary stains but are Gram-negative. They are always found associated