Serious disturbances of the internal organs apparently act as inciters of dreams in a considerable number of persons. Attention is quite generally called to the frequency of anxiety dreams in the diseases of the heart and lungs; indeed this relation of the dream life is placed so conspicuously in the foreground by many authors that I shall here content myself with a mere reference to the literature. (Radestock,[54] Spitta,[64] Maury, M. Simon, Tissié.) Tissié even assumes that the diseased organs impress upon the dream content their characteristic features. The dreams of persons suffering from diseases of the heart are generally very brief and terminate in a terrified awakening; the situation of death under terrible circumstances almost always plays a part in their content. Those suffering from diseases of the lungs dream of suffocation, of being crowded, and of flight, and a great many of them are subject to the well-known nightmare, which, by the way, Boerner has succeeded in producing experimentally by lying on the face and closing up the openings of the respiratory organs. In digestive disturbances the dream contains ideas from the sphere of enjoyment and disgust. Finally, the influence of sexual excitement on the dream content is perceptible enough in every one’s experience, and lends the strongest support to the entire theory of the dream excitation through organic sensation. Moreover, as we go through the literature of the dream, it becomes quite obvious that some of the authors (Maury,[48] Weygandt[75]) have been led to the study of dream problems by the influence of their own pathological state on the content of their dreams. The addition to dream sources from these undoubtedly established facts is, however, not as important as one might be led to suppose; for the dream is a phenomenon which occurs in healthy persons—perhaps in all persons, and every night—and a pathological state of the organs is apparently not one of its indispensable conditions. For us, however, the question is not whence particular dreams originate, but what may be the exciting source for the ordinary dreams of normal persons.