To encourage and ensure copulation and survival of the species.
The blood vessels carry nourishment to the fetus. It also assists in the male process that cause their hormones to grow.
primarily, male testes = testosterone, female ovaries = estrogen
the cells (something in the leaf, this is the only part i dont remember) fall into other leaves. when the wind blows, millions of cells are 'doing it', but only few make it.