1059. It hence becomes clear that the cortical substances relate to celestial things. In what manner they do so can be especially evident from the cortical substance of the cerebrum, and in the body from the quasi cortical substance of the kidneys. They are also the beginnings; there, in the cerebrum, is the formation of the [animal] spirits, to which spiritual things refer themselves and also flow forth thence. They are the beginnings of spiritual things, because spiritual things flow forth from them. They are also of a different color, namely, in themselves they are like the blood, either bright or red.