Figure 5 Cell walls, planes of cell division and the form of a plant body are illustrated in genera of green algae. A, Colony of Eudorina. The constituent cells are embedded in a gelatinous matrix. At the end of cell division daughter cells separate from one another. B, This shows what happens when division is always in one plane. Sharing of new cross-walls by daughter cells causes them to adhere to one another. The arrow indicates a cell that was about to divide. C, A vital new feature — the ability to change the plane of division generates branching systems of adherent cells (Stigeoclonium, low and high magnification views). (Micrographs courtesy B.E.S. Gunning)