Fig. 9. Following treatment with H₂O₂, gastrovascular flow within stolon tips virtually ceases. Oscillations in lumen width (µm) over time (seconds) for stolon tips of a control colony (filled circles) and a colony treated with 5 mmol l^–1 H₂O₂ (unfilled circles). The treated colony shows much smaller amplitudes and similar periods of oscillations; total stolon width was the same for both colonies.