Most of the examples I have presented of the influence of emotion of visceral origin in suggesting dream theories have had the stomach as their source. There can be no doubt that the stomach has enormous influence in this respect; its easily and constantly varying state of repletion, its central position and liability to press on other organs, its important nervous associations, together with the fact that sleep sometimes tends to impede its activity and initiate disturbance, combine to impart to it a manifold and extensive influence over the emotional state in sleep, and at the same time render the source of that emotional state peculiarly difficult for sleeping consciousness to detect. It is, however, easy to show that any pronounced or massive feeling continuing or arising during sleep may similarly lead to an emotional state calling for explanation at the hands of sleeping consciousness. Thus, falling asleep with toothache during a singularly close night, I once dreamed that I had committed murder, having apparently killed several persons, and that I was occupied, after arrest, in considering whether my act was likely to be regarded as an unpremeditated act of manslaughter. A headache, again, may be a source of dreams. Thus, falling asleep with headache, I dream that I am waiting for an express train to London; an express comes up to the platform, and I cannot ascertain if it is the train I want. The explanation seems obvious; railway travelling is a cause of headache, and it is therefore put forward in the dream, with accompanying imagery, to account for the sensations experienced. The actual sensation, as is always the case in dreams, that is, the headache, remains subconscious, and, indeed, totally unconscious; the imagery it suggests alone occupies the field of consciousness.[94] An entirely different type of dream may, however, be associated with headache. Thus I once dreamed that I was in a vast gloomy English cathedral, and on the wall I observed a notice to the effect that on such a day evensong would take place without illumination of the cathedral in order to avoid attracting moths. I awoke with slight headache. Here the cool, silent gloom of the cathedral is the symbol of what is desired to soothe the aching head, and the fantastic suggestion read on the notice is merely the theory of dreaming consciousness which knows nothing of the real reason of the wish.