Movement of Carbon from Vegetative Cells to Heterocysts in Anabaena cylindrica

Radioactive carbon assimilated by vegetative cells of Anabaena cylindrica in the light passed via an intrafilamentous route into heterocysts in the dark. After several hours, label per heterocyst approximated label per vegetative cell. Much of the label entering heterocysts was not available for diffusional exchange back into vegetative cells.