Abstract
In Fucus vesiculosus L., culture experiments have illustrated that within 2 mm of the apical cell, the origin of new meristems is inhibited. Further behind the apex, the influence of apical dominance gradually diminishes and beyond about 2 cm its effect is negligible. Polarity, which is so marked in the young plant, is not obvious in older tissues. There is no morphological difference between the branches produced from both cut surfaces of a segment of thallus. But, particularly in young tissue, there is a greater potential for regeneration from what is morphologically the upper end of a segment.