Abstract
By means of selection, Trifolium incarnatum plants were produced showing down to x = 1.1 chloroplasts per guard cell of stomata. Only two apoplastidic cells were seen. It could be shown that for a regular allocation of chloroplasts to daughter cells and for preventing apoplastidic cells to occur in higher plants, no special apportioning mechanism is required, but a non-random, more even distribution of chloroplasts in the mother cells may be sufficient. Such a distribution exists in mature cells and probably in meristematic cells as well. Thus the minimal number necessary for continuity in higher plants would be two chloroplasts for one mother cell, at least in Trifolium. The coupling of chloroplast division with cell division as found in lower plants is no longer maintained.
