To evolve, an organism must survive and reproduce. In earlier chapters we observed techniques plants have evolved for vegetative survival. In the last chapter we saw how angiosperms evolved techniques, to bring about the union of gametes. All of these activities would come to a dead end if the product of that union could not be preserved and allowed to develop. In this chapter we will see the developmental process. We will also observe the formation and function of a structure that is largely responsiblre for the dominance of gymnosperms and angiosperms on land--the seed.