Cell division in cells of Mycoplasma gallisepticum strains A5969 and S6 was studied. No differences were found between the two strains.During growth young cells either increase in length, in width, or in both directions. A second bleb may develop at various sites in the cell. Division appears to be related to the position of the bleb, and may be transverse or longitudinal. In addition, a divisional form resembling "budding" occurs, which may also produce equal or unequal daughter cells. As division proceeds, new membranes are formed and the cells appear to separate.Polysomes were found in the logarithmic phase, while in the lag phase only ribosomes were observed. With the growth of the cells polysomes and ribosomes migrate to regions where protein synthesis occurs.