This one haploid cell, the megaspore, then undergoes three successive mitoses to form the embryo sac, or the female gametopyhte.    From Wordnik.com.  [Nobel Lecture The Significance of Responses of the Genome to Challenge] Reference

Female cone develops two ovules on the upper surface of each cone scale; each ovule contains haploid megaspore.    From Wordnik.com.  [WN.com - Articles related to TV food advertisements promote imbalanced diets] Reference

The behaviour of the chromosomes in meiosis or reduction division both in the pollen mother-cells and in the megaspore mother-cells which give rise to the so-called embryo-sac are fully described by Gates.    From Wordnik.com.  [Hormones and Heredity] Reference