We feel satisfied that all sudden and abrupt transitions should be avoided. The state of sleep, apart from somnambulism, is one of natural repose; the organs of the body have their various functions appropriately modified; and we can not help thinking that to interrupt abruptly the course of nature, and throw, as it were, a dazzling light upon the brain, the functions of which are in abeyance, is unwise, and may prove injurious. Many persons suddenly awakened out of a deep sleep, complain afterward of severe headache. We conceive, therefore, that somnambulists who may be considered in a state of preternaturally profound sleep, ought not to be forcibly awakened. It is true that some somnambulists, like the servant girl described by Dr. Fleming, above referred to, have been awakened without after ill consequence, but as a general rule, the nervous system ought not to be subjected to any rude or unnecessary shock. The management of, and treatment of the somnambulist, must, it is obvious, depend very much on age, sex, temperament, and upon the causes, in particular--whether physical or mental--to which the affection may be ascribed. The most interesting circumstance connected with somnambulism is, that it brings palpably under our observation a preternatural state of being, in which the body is seen moving about, executing a variety of complicated actions, in the condition, physically, of a living automaton, while the lamp of the human soul is burning inwardly, as it were, with increased intensity; and this very exaltation of the mental faculties proves, incontestably, that the mind is independent of the body, and has an existence in a world peculiar to itself. A CHAPTER ON GIRAFFES. Of the many features which will hereafter stamp the nineteenth century as "Centuria Mirabilissima," not the least will be the vast number of animals and birds introduced into Europe, and the great stride made in our knowledge of Natural History during its progress. The precise date of the extinction of a genus or a species has interest; the dodo of the Mauritius and the dinornis of New Zealand have disappeared within the historical period, and there is no reason to suppose that such gaps have been, or will be, filled up by new creations. Second only in interest to the occurrence of these blanks in the list of living inhabitants of the surface of this globe is the record of the introduction of a new race into a part of our planet where it was previously unknown. In such instances the last twenty years have been prolific; the graceful bower-birds and the _Tallegalla_ or mound-raising birds, those wondrous denizens of the Australian wilderness, may now be seen in the Regent's Park for the first time in this hemisphere. For the first time, also, the wart hog of Africa there roots, and the hippopotamus displays his quaint gambols; and that "fairest animal," the giraffe, is now beheld in health and vigor, a naturalized inhabitant of Great Britain.