Three of these degenerate . The remaining megaspore divides to produce a gametophyte . The Megagametophyte develops within diploid tissue which is called the Nucellus . The gametophyte grows at the expense of the Nucellus which is largely consumed in this process. However some Nucellus remains intact, especially near the micropyle.
Several Archegonia develop at the micropylar end of the gametophyte .
Each of these contains a large egg . Multiple fertilizations frequently occur and the resulting embryos compete for nutrients . Eventually one takes over and grows to maturity inside the megagametophyte. Diagram of a Mature Ovule Mature Ovule of Pinus - Note the large eggs which make up the greatest part of each archegonium. Note the megagametophyte which has grown inside the Nucellus.