CELLULAR CHANGES ACCOMPANYING THE SWARMING OF PROTEUS MIRABILIS: II. OBSERVATIONS OF STAINED ORGANISMS

This paper describes the changes in nuclear complement, cytoplasm, and cell wall which take place when short rods of Proteus mirabilis differentiate into long swarmers. In the swarmers themselves, definite cellular units are mapped out at intervals of 1.2 to 1.8 μ. These units consist of a nucleus (or paired nuclei) and the adjacent cytoplasm, there being apparently no cross septa between successive units. The cytology of the swarmers has been compared with that of long forms of P. mirabilis induced by penicillin, lithium chloride, ultraviolet light, and gamma radiation. Depending on the inducing agent and dosage, such long forms frequently have abnormal-looking nuclei and malformed cell walls, and thus contrast strikingly with the spontaneously arising swarmers.