Cytokinesis in Gaffkya tetragena.

There is little agreement as to the manner of division of the cytoplasm of the bacterial cell. This may be due to the use of different stains, techniques, and organisms. Also, most of the workers did not have the advantages provided by the presence of a stained nucleus to correlate with septum formation. At least one exception was DeLamater (1952) who not only reported a nucleus in a Micrococcus but also published a photograph showing a "cell plate". He failed, however, to indicate its origin. Knaysi (1951) states that "the cytoplasm is divided by inward (centripetal) growth of the cytoplasmic membrane forming a septum or plate across the cytoplasm." Subsequently, each sister cell deposits its own cross wall in the middle of the cross plate. Bisset (1950) reports that there is a difference in the mechanism of cellular division as regards the rough and smooth types of cells. For the smooth type, he states that "when the cell is about to divide, a transverse septum, derived from the membrane, develops across the middle of the cell. The cell wall is then secreted at the edges of the new septum and grows inwards dividing the cell." In the division of the rough type of cell, it is stated also that the septum originates from the cell membrane. These are the more recent views on cytokinesis in the bacteria, and a review of the older literature will be omitted.