Cell Division in Oedogoniu M III. Golgi Bodies, Wall Structure, and Wall Formation in O. Cardiagum

Abstract

The structure of the ring in o. cardiacum is described; it is laid down adjacent to a circumferential weakening in the inner wall layer (present in interphase cells as well) which predicts precisely the rupture site. In basal daughter cells, this weakening is derived originally from a discontinuity in the basal lip of the ring itself. Two types of caps are formed; the classical series of single caps in sequence in apical daughter cells is matched by the invariable formation in basal daughter cells of a single large cap, which has added to it one tier per division, the next ring being formed each time adjacent to this "tiered" cap. The golgi bodies become hypertrophied early in mitosis (after the ring has been initiated); they remain thus during cell extension that follows wall rupture. However, once the septum reaches its final position forming a new cross wall, the golgi bodies in the ba8al daughter cell revert to the interphase condition, while the golgi bodies in the apical daughter cell remain hypertrophied during further extension. The cytochemical staining properties of the cell wall with silver-hexamine are described; peroxidation before staining induces a reaction in two types of golgi vesicles, and also in a diffuse fibrillar material in the vacuole, as well as in the cell wall structures. The septum vesicles are essentially unreactive, but the new cross wall reacts very strongly. The possible relationship of the golgi apparatus to both cell wall deposition and turgor pressure control is discussed.