The abscission process in emasculated tomato flower pedicels was investigated anatomically. Six days after emasculation, cells in the epidermal tissue in the abscission zone initially enlarged ; two days later, cells in the cortical region enlarged. Ten days after emasculation, cell enlargement spread toward the vascular bundles and then to the inner cortical parenchymatous region and to the pith. Finally, the enlarged cells separated from each other and formed large intercellular cavities ; the unpollinated flower abscised along this line from its weight 14 days after emasculation.