: moral practice of doing good. Reading the biographies of men remarkable for high and practical morality, and well-written works of moral fiction, contributes materially to the same end. This course, he affirms, when skilfully and inflexibly pursued, will infallibly strengthen and enlarge the moral organs, and confirm the persons subjected to its influence in habits of virtue. He represents the perfect physical education of the brain as consisting in the competent exercise of every part of it, so that each of its organs may possess due strength and activity and be itself healthy, and that there may exist between them the equilibrium necessary to the health and regulated action of the whole. If one or more organs or parts of the brain be exercised too much, they may become exhausted and debilitated, or excited to inflammation or a condition bordering on it, and not less truly morbid; while other parts, being exercised too little, or not at all, will be enfeebled by inaction; and thus must the health, not only of the brain, but of the whole system, suffer: for the brain being one of the ruling viscera of the animal economy, any derangement of it must injure the condition of all the others. He adds the position that the cerebral organs are liable to become exhausted or inflamed, according to their character when small, phlegmatic, and feeble, they are easily prostrated by severe exercise; when large, high-toned, and vigorous, intense exercise inflames them, or produces in them such irritability and inordinate action as to derange the balance of the brain, induce mental irregularities, and lay the foundations of cerebral disease. This view of the subject shews the propriety and advantage of pupils pursuing several studies or modes of mental exercise at the same time, instead of being confined exclusively to one. It suggests, moreover, the reason of it; for by changing from one study to another successively in the same day, those who are cultivating science and letters not only learn much more than they could under confinement to a single study, but do so with less exhaustion and danger to health. By closely studying one branch of knowledge, in other words, by labouring all day with one cerebral organ, it becomes exhausted and dull; and, when thus worn out by toil, it is not merely unfit to continue its exercise with due effect, and to master its task, but its health is endangered, if not actually injured. On the contrary, when the pupil feels himself becoming unfit for one study and passes to another, he engages in the latter with fresh and active organs, and makes rapid progress in it until, beginning to be again fatigued and dull, he changes to a third, or returns to that which he had relinquished, and finds the exhausted organs re invigorated by rest. A pupil should never be urged to an excessive exercise of feeble cerebral organs, it being both useless and dangerous. It is useless because he can in no way become respectable himself, or render high services to others, with such organs; and it is dangerous, because it may impair his intellect and destroy his health. For the same reason, a youth should neither be encouraged nor permitted to persevere to excess in the exercise of highly sensitive and vigorous organs: such practice would be like exposing an irritable or an inflamed eye to a glare of light, or assailing a phrenitic brain with piercing sounds. By a strict observance of these precepts in seats of education, it is Dr. C.'s opinion that much time might be saved which is now wasted, much evil prevented, and much good accomplished. The necessity of their enforcement is strengthened by the fact that children and youth of precocious and large developments, with unusually active and vigorous talents, generally possess delicate and sometimes feeble constitutions: their systems are, therefore, the more easily deranged, and should be guarded with the greatest care. Dr. Caldwell's philosophy, and his practical instructions on the all-important subject of "Physical Education," are but very partially developed in the preceding selections, which aim at little beyond the offering of inducements to investigate his doctrines, and to apply them in the nursery, the school-room, and the wide theatre of social life, in its manifold and complicated relations. His principles and views are well-illustrated in many places, and improved in others, by the apposite and perspicuous notes engrafted upon his work by its British editor; and in this extended form the volume merits a high degree of consideration from every person-parent or teacher who is intrusted with the corporeal or mental superintendence of the young and the inexperienced. J. K. THE REPTILES AND AMPHIBIA OF BRITAIN, * A SYSTEMATIC arrangement of the British Aves and Mammifera having already appeared in the Analyst, it occurred to me that a similar Catalogue of the remaining three Classes of British Vertebrata might prove acceptable to the zoological student. If the attempt be approved of, I may, probably, be induced to follow it up by catalogues of the British animals belonging to one or more of the Invertebrate Classes, particularly the Testaceous Mollusca, and the Zoophytes. I cannot, perhaps, adduce more strong and unanswerable arguments for the distribution of the Amphibia into a distinct Class, than those which Dhéré has brought forward, on the authority of Blainville, in support and vindication of this view of the subject. I shall, therefore, take the liberty of almost literally transcribing the paragraph in which those arguments are exposed :—“ In separating the Amphibia from the Reptiles, we follow," says Dhéré, "the classification of M. de Blainville; who considers them as a distinct Class, connecting the Reptiles with the Fishes. In fact, the skeleton, of a more mucous and less calcareous nature than that of Reptiles, the articulation of the head by two condyles, the naked and viscous condition of the skin, the absence of claws and of ribs, or the existence of the latter in a merely rudimentary form, the respiration at first branchial and afterwards pulmonary, the defect of an organe excitateur in the male, and fecundation without copulation, the peculiar envelope of the ova, and the metamorphoses which the animals in question exhibit in their progress from the ovum to the adult state, constitute characters sufficiently numerous and important to justify this separation; and, moreover, to prove that the Amphibia can never conform to the generalities exhibited by the Reptiles."+ In the construction of this Catalogue, I shall rely, with some few exceptions which my own observation and experience may seem to justify, on the works of Fleming and Jenyns, with respect to the Reptiles and Amphibia, and of Yarrell, as regards the Fishes. Nor is it my intention to attempt, in imitation of my very able and enterprizing predecessor, any sweeping plans of reform in the arrange * See vol. iii., page 197; and vol. iv., page 67. + Dhéré, De la Nutrition dans la Série des Animaux, page 57. my ment and nomenclature of the animals which constitute the subjects of list. Reforms in science, like those in the constitution and government of empires, can only be efficient and salutary when emanating from an enlightened and profoundly experienced spirit, and conducted with an extraordinarily cautious and temperate hand. The writer, to whom I have just adverted, has, both in his Catalogue of British Birds and Mammalia, advanced many steps which he will find it, after all, necessary to retrace; and neglected almost as many others which might have been taken with equal safety and advantage. Much more knowledge, again, has been acquired, respecting the first two than the three inferior Classes of Vertebrated Animals, in their distinctive characters and habits. Influenced by these various considerations, and warned by the failure of my predecessors in the difficult path of zoological reform, I shall content myself with following the track marked out by Jenyns and Yarrell; and reserve, for a season of greater leisure and more deliberate reflection, the exposition of my views upon the subject of a reform of the nomenclature of British Fishes. Observations.-Among the evidences of design exhibited in the works of creation, there are none, in my opinion, more striking and conclusive than that which is displayed by the various animals of the Class, the members of which have just been enumerated. With the tadpole, or young of the Frog family, every common observer must be acquainted. It lives exclusively in the water; swims about after the manner, and exhibits many of the characters and all the habits, of the fish. For this purpose, it is provided with gills, instead of lungs, for its respiratory organ; with a tail, and a horny beak or muzzle. It is perfectly destitute of limbs; and the organs destined, at a subsequent period, to execute the office of lungs, exist merely in a rudimentary condition. It is, in fact, an aquatic animal, fitted only to live in water; and incapable of respiring the common atmosphere. No sooner, however, has it attained a certain age, than an extraordinary change of organization and economy, peculiarly fitting it for the new life on which it must now enter, is accomplished. The horny muzzle and tail are detached; the gills shrink, and are withdrawn; the previously dor |