INTRODUCTION.

NIMAL life is constantly claiming our attention. Animals supply us with food; minister to our pleasures; transport us from place to place. The more we travel, the more widely do we recognise the diffusion of animal life; the more diligently we search, even in the pools, and fields, and woods of this country, the more novelties in animal life do we discover; the more perfect we render our microscopes, the more minute living creatures do we recognise, even in the water we drink.

In speaking of animals, and, indeed, of every created thing in the world, we continually have the word Nature on our lips. We use this word in many different senses. Perhaps the most general is that which defines Nature as "the world of matter, all that is created or has being, together with the forces inherent in the matter, and the laws according to which they act."

The knowledge of this stupendously vast whole was by the ancients termed Physics: we speak of it as Natural Science; and since it has been necessary to subdivide Nature, for purposes of study, the Science of Nature has been subdivided also into branches which are termed the Natural Sciences.

The Natural Sciences relate either to the products of Nature considered by themselves; or they teach us to apply them to our own use: in other words, they are either theoretical or practical. An instance of the latter is Agriculture; of the former, Natural History.

In considering the products of the earth, the first division we can make is into Organic and Inorganic bodies. The Greek word organon, from which these terms are derived, signifies an instrument, a tool. Hence organic bodies are those which possess instruments for locomotion, and the power of using them, which is Life. Inorganic bodies, on the other hand, possess none; there is no mutual dependence between the parts; each exists for itself, and when separated from the whole does not cease to be that which it was before. Inorganic bodies are Minerals : organic, Plants and Animals. Hence the branch of Natural History which treats of the former is Mineralogy, of the latter, Botany and Zoology, or the Science which treats of creatures that have life. In its widest sense, this science includes the description of the external forms of animals, as well as of their internal structure-Anatomy. In some works on Natural History, the term a perfect or an imperfect animal is frequently met with. This needs some explanation, as, properly speaking, every animal is perfect of its kind. But as animals may be arranged, as we shall hereafter show, in a descending series, of which the first object in importance is Man, those animals are described, for convenience sake, as perfect, whose organs approach nearest to those of Man, which may be taken as a standard of completeness: those, again, are described as imperfect, whose organs depart most widely from that standard.

The organs and functions peculiar to animals may be divided into two classes; the vegetative, which are shared by animals in common with plants; and the animal, which belong to Man and the brutes only. To the first class belongs nutrition and its organs: to the second, the organs of sense, the organs of motion, and the nervous system. It is only in Man that these are met with in the highest development. As we descend in the scale of animals, we perceive one organ after another gradually decrease in importance, and at last entirely disappear, until in the lowest forms of living things, such as those termed Infusoria, we find nothing but a gelatinous mass perforated by an intestinal canal. In like manner the hard, bony framework, called the Skeleton, which supports the muscles, the brain, and the spinal cord in Man, appears less and less developed as we descend in the scale of creation, until in the Tadpole we find only the rudiments of the skull and a vertebral column without limbs.

To understand this progressive development which the Almighty has been pleased to ordain among the creatures he has placed upon his earth, it is necessary to adopt some sort of classification. Without this we should be bewildered by the enormous quantity of living things, be unable to turn to account the observations of others, or communicate to them

our own.

The foundation of all classification is the Species. A species includes all individuals that have greater similarity to each other than to other similar creatures: who can propagate themselves, with such a degree of likeness between themselves and their young that it can be inferred that they all might have sprung from a single pair. When we speak of specific character, we mean the collection of all those characteristics which are shown to be permanent. Less important differences, by which individuals of a species vary among themselves, are called varieties. The product of the union of two species closely allied to each other is called a Hybrid. For instance, the horse and the ass are both species of the same genus: their product is the hybrid called a mule.

By Genus we mean a group formed of like species, as species was formed of like individuals. Occasionally a species is found which differs so remarkably from all others, that a genus has to be made especially for it. Generic character must be common to all the species in the genus, and can only be obtained by a comparative study of all these species. Hence genera are being continually altered as our knowledge increases in extent and minuteness.

All animals bear two names, indicating their genus and their species. This was a plan introduced by Linnæus; and Latin was employed by him as being more universally known than any other language. The first name denotes the genus, and must be a noun substantive; the second name denotes the species, and may be either a noun or an adjective. Thus the name of the common Dog is Canis familiaris, where Canis is a substantive and familiaris an adjective; while that of the Lion is Felis Leo, where both words are substantives.

Genera, again, are grouped together into Orders and Classes for facility of reference, the similarities on which such arrangement is based becoming, of course, wider and wider as we ascend. As the rings on the water of a lake, when a stone is thrown in, become wider and wider until they include at last the entire surface, so the arrangement of the Animal Kingdom, starting from the central point of the species, widens out, circle by circle, until it includes the whole creation.

In this manner we arrive at a map, as it were, of the principal divisions into which created things may be divided. But in order to recognise with ease where we are in our map,

and to find the name of any animal we may be examining, a System is necessary. Cuvier compared a system to a dictionary, in which the properties help us to discover the name, instead of the name teaching us the properties. A system to supply an easy means of finding out the name must be artificial: i.e., it must be based upon the resemblances and differences of a single set of organs. Such was the Sexual System, invented by Linnæus. No arbitrary system is possible in the animal kingdom. We there must seek for another kind of system, called a Method. "The chief object of Methods is," says a living author, "not so much to find the names readily, as to unite in an unconstrained manner those natural products which, in the greatest number of respects, correspond. They are founded, not on a single organ, or system of organs, but on the whole structure. If an object be seen only on one side, on the north or south, east or west, just so many partial representations of it will be obtained as there are points of view; but he only who observes it in all directions is able to form a judgment of its nature and being. This is the advantage of a natural method over artificial systems; it does not forget the centre in the circumference, but, comprising all the parts and properties of animals in its estimate, it allots to them a place in the arrangement according to their structure, and to the importance which belongs to them in the economy of nature, and so combines them in a great organic whole."*

It was long before such a method was devised in any useful shape. The great Greek philosopher, Aristotle (B.C. 384—322), was the first to attempt it. He divided animals broadly into two classes: those that have blood, and those that have not; and then subdivided these two. At a later date, the works of the ancients, on natural objects, are little more than records of disjointed facts or opinions, without order, plan, mutual bearing, or a definite purpose. Hence the little comparative progress in zoological science, and the mistakes and absurdities which long prevailed among nations the most civilised and refined.

It was nearly two thousand years after the death of Aristotle before there arose a man of sufficiently commanding genius to complete the structure of which he had laid the foundation. Linnæus was born in Sweden in 1707. In the "Systema Naturæ," puplished in 1735, he made known to the world the arrangement which, with certain alterations, is still followed. The Animal Kingdom, which we are now considering, he divided into six Classes, taking as his basis the Circulation of the Blood. His Classes are-I. Mammalia. II. Birds. III. Reptiles. IV. Fishes. V. Insects. V. Insects. VI. Worms. The modifications of this system are due to the increased study of Anatomy. Cuvier, the great French Anatomist, born at Paris in 1769, divided animals into Vertebrate and Invertebrate, according as they had, or had not, a skeleton, of which the primary and essential portion is the vertebra. He further arranged them in a descending scale, beginning with Man. It is this system that we, in the main, purpose to follow. The Class Mammalia will be subdivided in the present work into the following groups of Animals

I. FOUR-HANDED; II. WING-HANDED; III. INSECT-EATING; IV. GNAWING; V. FLESHEATING; VI. THICK-SKINNED; VII. RUMINATING; VIII. TOOTHLESS; and IX. POUCHBEARING.

In the preparation of this History we have attempted to present a popular Work to the public, which should at the same time fairly represent the results of modern science. We have

*Van der Hoeven. "Hand-book of Zoology," p. 29.

avoided technicalities, or, when obliged to employ them, explained them; employed English terms wherever it was practicable; and enlivened our descriptions by numerous anecdotes, derived from a great variety of trustworthy sources.

A large number of ILLUSTRATIONS will be found interspersed. Some exhibit the animals described, in their homes and haunts; thus rendering their form and character agreeably familiar to the eye. Others present the skeleton to view, so admirably adapted to afford mechanical support to different portions, as well as the body generally; to provide a solid basis for the attachments of the muscles, which are to effect all movements, and to give protection to the vital organs, but more particularly to the central parts of the nervous system. Of these the last is the circumstance that has the greatest influence in determining the principles on which the osseous framework is constructed. In the nervous system of all the Mammalia, the brain— which may be considered as the anterior extremity of the spinal marrow, only much enlarged by an additional mass of nervous substance-is the most important part; hence of this, as well as of the skull, which defends it from injury, and which, in size, shape, weight, and position, has a relation to the entire skeleton, engravings are numerous. So are they also of the teeth, since their structure and arrangement at once indicate the nature of the animal's appropriate food; and, consequently, afford the Naturalist most important characters for establishing a systematic classification-and more especially of quadrupeds-where the differences among the teeth are very considerable. To these are added other engravings of peculiarities of structure, as the hand, the fore leg, the foot, the paw.

In the present Edition we have revised the whole work, removed some minor inaccuracies which it was impossible to avoid in a first issue, added fresh engravings wherever we thought it necessary, and, as far as lay in our power, have incorporated in it the latest discoveries of modern scientific investigations. Our succeeding volumes will be reissued upon the same plan of revision.