Quite irrespective of the house symbolism, any other suitable object may be employed for the representation of these parts of the body which excite the dream. “Thus the breathing lungs find their symbol in the flaming stove with its gaseous roaring, the heart in hollow boxes and baskets, the bladder in round, bag-shaped, or simply hollowed objects. The male dream of sexual excitement makes the dreamer find in the street the upper portion of a clarinette, next to it the same part of a tobacco pipe, and next to that a piece of fur. The clarinette and tobacco pipe represent the approximate shape of the male sexual organ, while the fur represents the pubic hair. In the female sexual dream the tightness of the closely approximated thighs may be symbolised by a narrow courtyard surrounded by houses, and the vagina by a very narrow, slippery and soft footpath, leading through the courtyard, upon which the dreamer is obliged to walk, in order perhaps to carry a letter to a gentleman” (Volkelt, p. 39). It is particularly noteworthy that at the end of such a physically exciting dream, the phantasy, as it were, unmasks by representing the exciting organ or its function unconcealed. Thus the “tooth-exciting dream” usually ends with the dreamer taking a tooth out of his mouth. The dream phantasy may, however, not only direct its attention to the shape of the exciting organ, but it may also make the substance contained therein the object of the symbolisation. Thus the dream of intestinal excitement, _e.g._, may lead us through muddy streets, the bladder-exciting dream to foaming water. Or the stimulus itself, the manner of its excitation, and the object it covets, are represented symbolically, or the dream ego enters into a concrete combination with the symbolisation of its own state, as _e.g._, when, in the case of painful stimuli, we struggle desperately with vicious dogs or raging bulls, or when in the sexual dream the dreamer sees herself pursued by a naked man. Disregarding all the possible prolixity of elaboration, a symbolising phantastic activity remains as the central force of every dream. Volkelt,[72] in his finely and fervently written book, next attempted to penetrate further into the character of this phantasy and to assign to the psychical activity thus recognised, its position in a system of philosophical ideas, which, however, remains altogether too difficult of comprehension for any one who is not prepared by previous schooling for the sympathetic comprehension of philosophical modes of thinking.