FIG. 2.

Growth pattern of E. hirae. The wall of a partially divided cell is shown diagrammatically. The layers of murein are added to the sidewall as shown on the sides of the figure. These move outward, are stretched, and eventually are autolyzed and discarded. The ingrowing septum is also added in an unstretched conformation as indicated by thick lines. When bisection occurs, the wall stretches and yields two daughter cells. The site for the ingrowth is located under a ridge that passes all around the equator of the cell.