mountains, and the sands of the sea, are replete with life. The waters, too, whether of the ocean or of the land, teem with animated beings. Scarcely is a particle of matter to be found that does not present inhabitants to our view; and a drop of ditch-water is a little world in itself, stored with inmates of corresponding magnitude.

The consideration of the anatomical structure and external conformation of the many thousands of living creatures that come under our view, would of itself occupy many volumes, were it presented in detail; and even the simplest outline in which it could be produced would require more space than can be devoted to it here. All departments of Nature are full of wonders; but this excels the rest in interest, and is proportionally more difficult to be studied; although men, contented with superficial knowledge, may fancy themselves masters of her secrets when they have merely learned to distinguish some hundreds of objects from each other.

Man, separated from all other animals by peculiarities of corporeal organization, not less than by those intellectual faculties which are not in any considerable degree participated by the other inhabitants of the globe, and who is capable of subsisting in every climate, from the arid regions of the torrid zone to the frozen confines of the poles, also belongs in some measure to the study of nature. But the consideration of man includes a multitude of subjects that do not properly belong to Natural History, in the limited sense in which we use the term. It might even be said that it embraces all human knowledge. Thus, the constitution of the human mind, and the structure of the human body, as well as its healthy

and morbid phenomena, together with the means of regulating the former and of counteracting the latter, may certainly be included in it.

Natural history, however, in its more limited acceptation, may be considered as comprehending the three great kingdoms of Nature,—the mineral, the vegetable, and the animal,—the sciences treating of which are named Mineralogy, Botany, and Zoology. The first of these departments of knowledge comprehends, along with the consideration of simple minerals, that of the masses produced by the aggregation of these substances, and the changes effected upon them by natural causes. Botany teaches us to distinguish and arrange the subjects of the vegetable kingdom, points out the forms and functions of their organs, investigates their internal structure, traces them in their distribution over the surface of the globe, and makes known the various properties which render them noxious or useful to us. Zoology treats of the various tribes of animals, marks their external forms, compares their various organs, describes their habits, discloses the laws which regulate their distribution over the continents and islands, arranges them into families according to principles deduced from their structure, and in general makes us acquainted with all that belongs to their history. Although it is unnecessary here to offer any extended remarks on the cultivation of the vast field which is thus opened up to us, yet, the science of animals being intimately connected with the Series of Lives which we propose to offer to the public, it may not be improper to give a short account of its origin and progress.

In the History of Zoology, four eras are marked by

the names of four great cultivators of that science. All knowledge of nature must have commenced in the observation of individuals, or in an intuitive perception of their properties bestowed upon the first man. We may suppose, however, that at some period not remote from the creation of the human race men were left to their own resources, when they were necessarily forced to examine the nature and qualities of plants and animals, as well as of all natural objects with which they came into contact. The son would learn from the father, and impart to his descendants a certain degree of knowledge acquired by observation. Where the art of writing was unknown, science would advance but slowly; and even where it was practised, the privilege would probably belong to individuals or families, so that the mass would still be left to their ordinary resources. Those who lived in the remote ages antecedent to the Christian era probably knew as much of natural history as the unlettered peasant of our own age and country. Whatever may have been the acquirements of the priests, the sole depositaries of science in ancient India, Chaldea, and Egypt, they perished amid the revolutions of empires. The Sacred Scriptures, however, show that Moses, who was learned in all the wisdom of the Egyptians, had bestowed considerable attention on the animal world; but as these writings were not intended for our instruction in natural knowledge, the observations which they contain on the subject have no reference to systematic arrangement. In short, whatever may have been the knowledge possessed by the subjects of the Pharaohs, or the Hebrews and Greeks of the earlier ages, we do not find that it had assumed

any definite form, or constituted a body of doctrine, until the time of Alexander the Great. At this epoch the illustrious Aristotle collected the observations of his predecessors; added to them those, more extensive and more important, which were made by himself; and, although deeply engaged in the study of other subjects, succeeded in collecting a mass of facts, and in eliciting from them general principles, the accuracy of many of which might surprise us, did we not reflect that, in this department at least, he followed the true method by which the physical sciences have in our times received so vast an augmentation. He, however, stands alone among the writers of remote antiquity in this field; for, if others followed in his steps, their works have been lost.

Among the Romans, by whom the sciences were carried from Greece to Western Europe, there must have been many naturalists of considerable attainments; but the only writer of that nation whose descriptions have come down to us is Pliny the Elder, who flourished under Vespasian. His books on natural history are compiled from the writings of others, and may be considered as a general collection of all that was known in his time. Although he must have possessed opportunities of observing the many rare animals that were brought from all parts of the world to Rome, it does not appear that, by original observation, he added much to the mass of facts; still he may be viewed as marking the second epoch in the history of zoology, more especially as his works supplied the materials out of which naturalists in later ages have constructed their systems. As to Ælian, a Greek writer, whose treatise was also a

compilation, his merits were much fewer, and his absurdities more numerous than those of his predecessor. Both were fond of the marvellous, but he was eminently addicted to falsehood.

During the long ages of barbarism that succeeded the destruction of the Roman empire all the sciences were lost. On the revival of learning some feeble efforts were made to rescue natural history from its degraded condition; and at the commencement of the sixteenth century appeared several works on fishes, by Paolo Giovio, Pierre Belon, Rondelet, and Salviani. Belon wrote on birds also, and his observations are remarkable considering the period at which he lived. Conrad Gesner, a physician of Zurich, in his History of Animals, presented a compilation, arranged in alphabetical order, of all that the ancients had left on the subject; and Aldrovandi, after the labour of sixty years, left behind him an immense work on natural history, comprising no less than fourteen folio volumes. In the seventeenth century, we find our own Ray and Willughby among the most successful students of nature. Besides these celebrated individuals, there were others, such as Jonston and Redi, who laboured in the field of zoology; but perhaps the most original authors of this period were Swammerdam and Reaumur, whose minute observations, in entomology especially, have not been excelled in accuracy by those of any subsequent writers. It was not, however, until the middle of the eighteenth century, that a new era was formed by the labours of Linnæus, who was the first to collect all the known productions of nature, to class them according to simple principles derived from the observation of

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