Fig. 8. TEM micrographs of a regressed stolon treated with 5 mmol l^–1 H₂O₂. (A–C) The epitheliomuscular cells (EMCs) in a regressed stolon exhibit vacuolation of the cytoplasm (A). Treated stolons are sometimes contracted (B; as indicated by the space between the perisarc and the ectoderm). Cells of a regressed stolon have relatively normal appearing mitochondria (C) and compact nuclei with flocculent condensation of chromatin (A,B). (D,E) Cells in the tip of the regressed stolon are shrunken (D) compared to their control counterparts (e.g. Fig. 7D). Once a stolon regresses, the cell membranes in the tip form numerous small vesicles (E). P, perisarc; E, ectoderm; MG, mesoglea; N, nucleus; M, mitochondrion; V, vacuole, Ve, vesicle. Scale bars, 1 µm.