4040. When the skull and the coverings surrounding the brain are removed, wonderful sinuously curving and overlapping masses of tissue are visible, in which there are deposited what are called the cortical substances. Running out from these there are fibres which constitute the medulla of the brain. These fibres proceed from there by way of nerves into the body and perform functions there as the brain bids and chooses. All of this is in perfect accord with the heavenly form, for such a form is imprinted by the Lord on the heavens, and from the heavens on the things within the human being, in particular on his cerebrum and cerebellum.