Let me illustrate this effect in one of the simplest cases, that of the visual organ. If, when walking out on a dark night, a few points in my retina are suddenly stimulated by rays of light, and I recognize some luminous object in a corresponding direction, I am prepared to see something above and below, to the right and to the left of this object. Why is this? There may from the first have been a kind of innate understanding among contiguous optic fibres, predisposing them to such concerted action. But however this be, this disposition would seem to have been largely promoted by the fact that, throughout my experience, the stimulation of any retinal point has been connected with that of adjoining points, either simultaneously by some second object, or successively by the same object as the eye moves over it, or as the object itself moves across the field of vision. When, therefore, in sleep any part of the optic centres is excited in a particular way, and the images thus arising have their corresponding loci in space assigned to them, there will be a disposition to refer any other visual images which happen at the moment to arise in consciousness to adjacent parts of space. The character of these other images will be determined by other special conditions of the moment; their locality or position in space will be determined by this organic connection. We may, perhaps, call these tendencies to concerted action of some kind general associative dispositions. Just as there are such dispositions to united action among various parts of one organ of sense, so there may be among different organs, which are either connected originally in the infant organism, or have communications opened up by frequent coexcitation of the two. Such links there certainly are between the organs of taste and smell, and between the ear and the muscular system in general, and more particularly the vocal organ.[96] A new odour often sets us asking how the object would taste, and a series of sounds commonly disposes us to movement of some kind or another. How far there may be finer threads of connection between other organs, such as the eye and the ear, which do not betray themselves amid the stronger forces of waking mental life, one cannot say. Whatever their number, it is plain that they will exert their influence within the comparatively narrow limits of dream-life, serving to impress a certain character on the images which happen to be called up by special circumstances, and giving to the combination a slight measure of congruity. Thus, if I were dreaming that I heard some lively music, and at the same time an image of a friend was anyhow excited, my dream-fancy might not improbably represent this person as performing a sequence of rhythmic movements, such as those of riding, dancing, etc.