In sanguineous animals, in proportion as the blood becomes calm and separated the fact that the movement, based on impressions derived from each of the organs of sense, is preserved in its integrity, renders the dreams coherent, causes an image to present itself, and makes the dreamer think, owing to the effects borne in from the organ of sight, that he actually sees, and owing to those which come from the organ of hearing, that he really hears; and so on with those also which proceed from the other sensory organs.