The first introduction to this remarkable region comes to people in various ways. Some only once in their whole lives under some unusual influence become sensitive enough to recognize the presence of one of its inhabitants, and perhaps, because the experience does not repeat itself, come in time to believe that on that occasion they must have been the victims of hallucination: others find themselves with increasing frequency seeing and hearing something to which those around them are blind and deaf; others again--and perhaps this is the commonest experience of all--begin to recollect with greater and greater clearness that which they have seen or heard on that other plane during sleep. Among those who make a study of these subjects, some try to develop the astral sight by crystal-gazing or other methods, while those who have the inestimable advantage of the direct guidance of a qualified teacher will probably be placed upon that plane for the first time under his special protection, which will be continued until, by the application of various tests, he has satisfied himself that the pupil is proof against any danger or terror that he is likely to encounter. But, however it may occur, the first actual realization that we are all the while in the midst of a great world full of active life, of which most of us are nevertheless entirely unconscious, cannot but be to some extent a memorable epoch in a man's existence. So abundant and so manifold is this life of the astral plane that at first it is absolutely bewildering to the neophyte; and even for the more practised investigator it is no easy task to attempt to classify and to catalogue it. If the explorer of some unknown tropical forest were asked not only to give a full account of the country through which he had passed, with accurate details of its vegetable and mineral productions, but also to state the genus and species of every one of the myriad insects, birds, beasts, and reptiles which he had seen, he might well shrink appalled at the magnitude of the undertaking: yet even this affords no parallel to the embarrassments of the psychic investigator, for in his case matters are further complicated, first by the difficulty of correctly translating from that plane to this the recollection of what he has seen, and secondly by the utter inadequacy of ordinary language to express much of what he has to report. However, just as the explorer on the physical plane would probably commence his account of a country by some sort of general description of its scenery and characteristics, so it will be well to begin this slight sketch of the astral plane by endeavouring to give some idea of the scenery which forms the background of its marvellous and ever-changing activities. Yet here at the outset an almost insuperable difficulty confronts us in the extreme complexity of the matter. All who see fully on that plane agree that to attempt