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Embryological study of ovules from isolated flowers. (A) A few-nucleate female gametophyte on the 4th day; nuclei are indicated by arrowheads; the star indicates an invisible egg cell. (B) Mature embryo sac on the 8th day, with the egg apparatus (ec, sc) and one polar nucleus (arrowhead). (C) The enlarged egg cell (ec) and degenerated polar nucleus (arrowhead) on the 12th day. (D) Mature embryo sac with the egg apparatus (ec, sc) on the 16th day. Scale bar = 10 μm.
