370. It is to be noted that the very forms of a man's members, organs and viscera in respect of their actual structure, are from fibres that arise out of their beginnings in the brains, but that they are fixed by means of such substances and matters as are in the earths, and from the earths in the air and ether, and that this is effected by means of the blood. Therefore, in order that all things of the body may continue to exist in their formation, and thus be permanent in their functions, man must be nourished by material food, and be continually renewed.