Demonstration of a cell wall in the large bodies of Proteus vulgaris.

The ability of penicillin to induce morphological changes in various strains of Proteus is already well known from the investigations of Qrskov (1947), Lahelle (1948), Levaditi and Henry (1948), Dienes (1949), Tulasne (1949a,b, 1950), Fleming et al. (1950), Freundt (1950), Pulvertaft (1953), and von Prittwitz and Gaffron (1953). The ease with which Proteus produces spherical forms, so-called "large bodies", leads one to inquire about the fate of the cell wall during this transformation. Such a change in shape may result from either the rupture of the cell wall followed by the extrusion of the protoplasm or a change in the rigidity of the cell wall. The present investigation deals with a description of the morphological changes which occur in Proteus vulgaris strain OX19 when grown in the presence of penicillin and with attempts to demonstrate a cell wall in the different morphological forms.