The formation and development of large bodies in Proteus vulgaris OX-19. I. Bright phase contrast observations of living bacteria.

The appearance of diverse morphological forms in Proteus vulgaris OX-19 (Stempen and Hutchinson, 1951) stimulated interest in a cytological investigation of the organism to compare the chromatinic structures in the large bodies and other "atypical" forms with those in the "normal" rods. Cytological studies on large bodies of Proteus have been previously reported by KlienebergerNobel (1949), Tulasne (1949b), and Fleming et al. (1950). These reports deal with large bodies induced by exposure to low temperature or penicillin. The strain of Proteus used in the present investigation produces large bodies in sufficient numbers under normal cultural conditions for it not to be necessary to resort to the use of an abnormal environment.