At cyst formation in the 'giant' unicellular green alga Acetabularia, each cyst contains a single nucleus which subsequently undergoes several rounds of mitosis prior to gamete formation. Initially the nuclei form a syncytium which separates into individual gametes. This section shows a stage in gametogenesis where the syncytium has just begun to divide into uninuclear gametes. See Woodcock and Miller, 1973. Ultrastructural features of the life cycle of Acetabularia I Gametogenesis. Proptoplasma 77, 313-319.