While the confusions of dreaming are usually the union of unconnected streams of imagery which have, as it were, come from widely remote parts of the memory system to strike together at the narrow focus of shaping consciousness, in some rarer cases the fused images are really suggested by analogy and are not accidental. Maury records successions of dream imagery strung together by verbal resemblances; I have found such dreams rare, but other forms of association fairly common. Thus I once dreamed that I was with a dentist who was about to extract a tooth from a patient. Before applying the forceps he remarked to me (at the same time setting fire to a perfumed cloth at the end of something like a broomstick in order to dissipate the unpleasant odor) that it was the largest tooth he had ever seen. When extracted I found that it was indeed enormous, in the shape of a caldron, with walls an inch thick. Taking from my pocket a tape measure (such as I always carry in waking life) I founds the diameter to be not less than twenty-five inches; the interior was like roughly hewn rock, and there were sea-weeds and lichenlike growths within. The size of the tooth seemed to me large, but not extraordinarily so. It is well known that pain in the teeth, or the dentist's manipulations, cause those organs to seem of extravagant extent; in dreams this tendency rules unchecked; thus a friend once dreamed that mice were playing about in a cavity in her tooth. But for the dream first quoted there was no known dental origin; it arose solely or chiefly from a walk during the previous afternoon among the rocks of the Cornish coast at low tide, and the fantastic analogy, which had not occurred to waking consciousness, suggested itself during sleep.
The following dream illustrates an association of quite a different order: I imagined I was sitting at a window, at the top of a house, writing. As I looked up from my table I saw, with all the emotions naturally accompanying such a sight, a woman in her night dress appear at a lofty window some distance off and throw herself down. I went on writing, however, and found that in the course of my literary employment – I am not clear as to its precise nature – the very next thing I had to do was to describe exactly such a scene as I had just witnessed. I was extremely puzzled at such an extraordinary coincidence: it seemed to me wholly inexplicable. Such dreams, reduplicating the imagery in a new sensory medium, are fairly common, with me at all events, though I can not easily explain them. The association is not so much of analogy as of sensory media, in this case the visual image becoming a verbal motor image. In other cases a scene is first seen as in reality, and then in a picture. It is interesting to observe the profound astonishment with which sleeping consciousness apperceives such simple reduplication.
It sometimes happens that the confused imagery of dreams includes elements drawn from forgotten memories – that is to say, that sleeping consciousness can draw on faint impressions of the past which waking consciousness is unable to reach. This is a very important type of dream because of its bearing on the explanation of certain dream phenomena which we are sometimes asked to bow down before as supernatural. I may illustrate what I mean by the following very instructive case. I woke up recalling the chief items of a rather vivid dream: I had imagined myself in a large old house, where the furniture, though of good quality, was ancient, and the chairs threatened to give way as one sat on them. The place belonged to one Sir Peter Bryan, a hale old gentleman who was accompanied by his son and grandson. There was a question of my buying the place from him, and I was very complimentary to the old gentleman's appearance of youthfulness, absurdly affecting not to know which was the grandfather and which the grandson. On awaking I said to myself that here was a purely imaginative dream, quite unsuggested by any definite experiences. But when I began to recall the trifling incidents of the previous day I realized that that was far from being the case. So far from the dream having been a pure effort of imagination I found that every minute item could be traced to some separate source. The name of Sir Peter Bryan alone completely baffled me; I could not even recall that I had at that time ever heard of any one called Bryan. I abandoned the search and made my notes of the dream and its sources. I had scarcely done so when I chanced to take up a volume of biographies which I had glanced through carelessly the day before. I found that it contained, among others, the lives of Lord Peterborough and George Bryan Brummel. I had certainly seen those names the day before; yet before I took up the book once again it would have been impossible for me to recall the exact name of Beau Brummel, and I should have been inclined to say that I had never even heard the name of Bryan. I repeat that I regard this as, psychologically, a most instructive dream. It rarely happens (though I could give one or two more examples from the experience of friends) that we can so clearly and definitely demonstrate the presence of a forgotten memory in a dream; in the case of old memories it is usually impossible. It so happened that the forgotten memory which in this case re-emerged to sleeping consciousness was a fact of no consequence to myself or any one else. But if it had been the whereabouts of a lost deed or a large sum of money, and I had been able to declare, as in this case, that the impression received in my dream had never to my knowledge existed in waking consciousness, and yet were to declare my faith that the dream probably had a simple and natural explanation, on every hand I should be sarcastically told that there is no credulity to match the credulity of the skeptic.
The profound emotions of waking life, the questions and problems on which we spread our chief voluntary mental energy, are not those which usually present themselves at once to dream consciousness. It is, so far as the immediate past is concerned, mostly the trifling, the incidental, the "forgotten" impressions of daily life which reappear in our dreams. The psychic activities that are awake most intensely are those that sleep most profoundly. If we preserve the common image of the "stream of consciousness," we might say that the grave facts of life sink too deeply into the flood to reappear at once in the calm of repose, while the mere light and buoyant trifles of life, flung carelessly in during the day, at once rise to the surface, to dance and mingle and evolve in ways that this familiar image of "the stream of consciousness" will not further help us to picture.
So far I have been discussing only one of the great groups into which dreams may be divided. Most investigators of dreams agree that there are two such groups, the one having its basis in memories, the other founded on actual physical sensations experienced at the moment of dreaming and interpreted by sleeping consciousness. Various names have been given to these two groups; Sully, for instance, terms them central and peripheral. Perhaps the best names, however, are those adopted by Miss Calkins, who calls the first group representative, the second group presentative.
All writers on dreaming have brought forward presentative dreams, and there can be no doubt that impressions received during sleep from any of the external senses may serve as a basis for dreams. I need only record one example to illustrate this main and most obvious group of presentative dreams. I dreamed that I was listening to a performance of Haydn's Creation, the chief orchestral part of the performance seeming to consist chiefly of the very realistic representation of the song of birds, though I could not identify the note of any particular bird. Then followed solos by male singers, whom I saw, especially one who attracted my attention by singing at the close in a scarcely audible voice. On awakening the source of the dream was not immediately obvious, but I soon realized that it was the song of a canary in another room. I had never heard Haydn's Creation, except in fragments, nor thought of it at any recent period; its reputation as regards the realistic representation of natural sounds had evidently caused