Number of cell around which cell wall formation occurs during development of typical female gametophyte in angiosperms

Dear student,
In an angiosperm, inside the ovary is present one/many ovules and within each ovule is present an embryo sac(female gametophyte) each embryo sac undergoes one meiotic and three mitotic divisions, giving rise to total 8 nuclei, out of which 3 of them move towards one pole forming antipodals , these are partitioned by plasma membrane , three more cells migrate to the other pole forming egg apparatus, also surrounded by dense cytoplasm and plasma membrane.
In the middle two nuclei in close vicinity and stat free nuclear division with no formation of cell wall ,these are the polar nuclei. this complete apparatus of 7 cells(ceentral cell is in the middle in which polae nuclei lie) and 8 nuclei is surrounded collectively by a CELL WALL .