The nature-spirits are also responsible for whatever of truth there may be in all the strange fairy stories which are so common in certain parts of the country. Sometimes a temporary accession of clairvoyance, which is by no means uncommon among the inhabitants of lonely mountainous regions, enables some belated wayfarer to watch their joyous gambols; sometimes strange tricks are played upon some terrified victim, and a glamour is cast over him, making him, for example, see houses and people where he knows none really exist. And this is frequently no mere momentary delusion, for a man will sometimes go through quite a long series of imaginary but most striking adventures, and then suddenly find that all his brilliant surroundings have vanished in a moment, leaving him standing in some lonely valley or on some wind-swept plain. On the other hand, it is by no means safe to accept as founded on fact all the popular legends on the subject, for the grossest superstition is often mingled with the theories of the peasantry about these beings, as was shown by a recent terrible murder case in Ireland. To the same entities must be attributed a large portion of what are called physical phenomena at spiritualistic _seances_--indeed, many a _seance_ has been given entirely by these mischievous creatures; and such a performance might easily include many very striking items, such as the answering of questions and delivery of pretended messages by raps or tilts, the exhibition of "spirit lights," the apport of objects from a distance, the reading of thoughts which were in the mind of any person present, the precipitation of writings or drawings, and even materializations. In fact, the nature-spirits alone, if any of them happened to be disposed to take the trouble, could give a _seance_ equal to the most wonderful of which we read; for though there may be certain phenomena which they would not find it easy to reproduce, their marvellous power of glamour would enable them without difficulty to persuade the entire circle that these phenomena also had duly occurred, unless, indeed, there were present a trained observer who understood their arts and knew how to defeat them. As a general rule, whenever silly tricks or practical jokes are played at a _seance_, we may infer the presence either of low-class nature-spirits, or of human beings who were of a sufficiently degraded type to find pleasure in such idiotic performances during life. [Sidenote: Communicating Entities.]