Two kinds of cell packets of Micrococcus luteus, one having teichuronic acids (TUA) in the cell wall and the other lacking TUA, have been independently reported by two groups of workers. A comparison by scanning electron microscopy of these packets provided a possibly consistent interpretation for the seemingly conflicting opinions whether TUA were involved in packet induction. It was strongly suggested that the packets having TUA in the wall were rigidly maintained by a bridging structure of the outermost layer of the peripheral wall, while the packets lacking TUA showed low contribution of the outermost layer to the bridging structure probably due to the absence of TUA.