584. From this it is now plain that there is a correspondence between natural and spiritual births. From this correspondence it follows that in describing re-births one can not only speak of conception, gestation in the womb, birth and upbringing, but such phases actually occur. What they are like may be seen discussed in the section on regeneration. All I will say now is that the human semen is conceived inwardly in the understanding, formed in the will, and transferred from there to the testicle, where it clothes itself with a natural covering; and so it is ejected into the womb and comes into the world. There is as well a correspondence between a person's regeneration and everything in the vegetable kingdom. That is why in the Word too man is described by a tree, his truth by a seed, his good by a fruit. A useless tree can as it were be re-born, and afterwards bear good fruit and good seed, as is clear from the practice of grafting and inoculation. Even though in these cases the same sap rises from the root through the trunk* to the point of the graft or inoculation, it is none the less converted into good sap and produces a good tree. It is much the same in the church with those who are grafted into the Lord, as He teaches in these words: