possesses the power of combining and arranging them, to form a new creation of its own], this is called imagination, and it may be accompanied by agreeable or painful associations.

Man being endowed with superior privileges, possesses the faculty of connecting his general ideas with particular signs. These are more or less arbitrary, easily fixed in the memory, and serve to suggest the general ideas, which they were intended to represent. We apply the term symbols to designate these signs when associated with our general ideas, and they form a language when collectively arranged. Language may be addressed either to the ear or to the eye; in the former case it is termed speech, in the latter, hieroglyphics. Writing is a series of images, by which the elementary sounds are represented to the eye [under the form of letters]. By combining them [into words], the compound sounds of which speech is composed are readily suggested. Writing is therefore an indirect representation of our thoughts.

This power of representing general ideas by particular signs or symbols, which are arbitrarily associated with them, enables us to retain an immense number of distinct. ideas in the memory, and to recall them with facility. Innumerable materials are thus readily supplied to the reasoning faculty and to the imagination. The experience of individuals is also communicated by written signs to the whole human species, and by this means the foundation is laid for their indefinite improvement in knowledge through the course of ages.

The art of printing, by multiplying copies, has insured the permanence of knowledge, and has afforded a powerful aid to the intellectual progress of the species.

This capacity for indefinite improvement forms one of the distinguished characters of human intelligence.

The most perfect animals are infinitely below Man, in respect to the degrees of their intellectual faculties; but it is nevertheless certain that their understandings perform operations of the same kind. They move in consequence of sensations received; they are susceptible of lasting affections; and they acquire by experience a certain knowledge of external things, sufficient to regulate their motions, by actually foreseeing their consequences, and independently of immediate pain and pleasure When domesticated, they feel their subordination. They know that the being who punishes them may refrain from doing so if he will, and they assume before him a supplicating air, when conscious of guilt, or fearful of his anger. The society of man either corrupts or improves them. They are susceptible of emulation and of jealousy; and, though possessed among themselves of a natural language, capable of expressing the sensations of the moment, they acquire from man a knowledge of the much more complicated language through which he makes known his pleasure, and urges them to execute it.

We perceive, in fact, a certain degree of reason in the higher animals, and consequences resulting from its use and abuse, similar to those observed in Man. The degree of their intelligence is not far different from that possessed by the infant mind, before it has learned to speak. But, in proportion as we descend in the scale of creation to animals far below man in organization, these faculties become more languid; and, in the lowest classes, they are reduced to certain motions obscurely indicating some kind of sensation, and the desire of avoiding pain. The degrees of intellect between these extremes are infinite.

Dogs, cats, horses, birds, and other animals, may have their original faculties modified by personal experience; and they are accordingly trained to the performance of those extraordinary feats which in all countries form a favourite amusement of the people. "By experience," says Mr. Hume, "animals become acquainted with the more obvious properties of external objects; and gradually, from their birth, treasure up a knowledge of the nature of fire, water, stones, earth, heights, depths, &c. The ignorance and inexperience of the young are here plainly distinguishable from the cunning and sagacity of the old, who have learned by long observation to avoid what hurt them, and pursue what gave ease and pleasure. A horse that has been accustomed to the field, becomes acquainted with the proper height he can leap, and will never attempt what exceeds his force and ability. An old greyhound will trust the more fatiguing part of the chase to the younger, and will place himself so as to meet the hare in her doubles; nor are the conjectures which he forms on this occasion founded on any thing but his observation and experience. This is still more evident from the

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effects of discipline and education on animals, who, by the proper application of rewards and punishments, may be taught any course of action the most contrary to their natural instincts and propensities. Is it not experience which renders a dog apprehensive of pain, when you menace him, or lift up the whip to beat him? Is it not even experience which makes him answer to his name, and infer, from such an arbitrary sound, that you mean him rather than any of his fellows, and intend to call him when you pronounce it in a certain manner and with a certain accent?

There exists, however, in a great number of animals, a faculty different from intelligence, called instinct. This power causes them to perform certain actions necessary to the preservation of the species, but often altogether removed from the apparent wants of the individual. These are often so very complicated and refined, that it is impossible to suppose them the result of foresight, without admitting a degree of intelligence in the species performing them, infinitely superior to what they exhibit in other respects. The actions proceeding from instinct are still less the effect of imitation, for the individuals executing them have sometimes never seen them performed by others. The degree of instinct is by no means proportioned to the general intelligence of the species; but it is in those animals which, in their other actions, manifest the utmost stupidity, that instinct appears most singular, most scientific, and most disinterested. It is so much the property of each entire species, that all individuals exercise it in precisely the same manner, without ever attaining to higher degrees of cultivation.

"Every other animal but Man, from the first outset of the species and of the individual, is equal to his task; proceeds in the shortest way to the attainment of his purpose, and neither mistakes the end nor the means by which it is to be obtained. In what he performs, we often justly admire the ingenuity of the contrivance and the completeness of the work. But it is the ingenuity of the species, not of the individual; or rather, it is the wisdom of God, not the deliberate effect of invention or choice, which the created being is fitted to employ for himself. His task is prescribed, and his manner of performing it secured. Observe the animals most remarkable for a happy choice of materials, and for the curious execution of their works. The bird, how unvaried in the choice of the matter she employs in the structure, or in the situation she has chosen for her eyrie or nest! Insects, most exquisitely artful in the execution of their little works, for the accommodation of their swarms, and the lodgment of their stores; how accomplished in their first and least-experienced attempts! how uniform and unchanged in the last! Nature appears to have given to the other animals a specific direction to the means they are to employ, without any rational conception of the end for which they are to employ them."

Thus, the working bees, from the creation of the world, have always constructed edifices of great ingenuity, upon principles deduced from the highest branches of geometry, for the purpose of lodging and nourishing a posterity which is not even their own.

"It is a curious mathematical problem," observes Dr. Reid, "at what precise angle three planes which compose the bottom of a cell in a honey-comb ought to meet, in order to make the greatest saving, or the least expense, of material and labour; and this is the very angle in which the three planes in the bottom of a cell do actually meet. Shall we ask here, who taught the bee the properties of solids, and to resolve the problems of maxima and minima? We need not say that bees know none of these things. They work most geometrically, somewhat like a child, who, by turning the handle of an organ, makes good music, without any knowledge of music. The art is not in the child, but in HIM who made the organ. In like manner, when a bee makes its comb so geometrically, the geometry is not in the bee, but in that Great Geometrician who made the bee, and made all things in number, weight, and measure."

The solitary bees and wasps construct very complicated nests for the reception of their eggs. From each egg there proceeds a worm which has never seen its mother, which knows not the structure of the prison enclosing it; and yet, after it has undergone its metamorphosis, will construct another nest, precisely similar, to contain its own egg.

No satisfactory explanation can be given of the phenomena of instinct, except we admit that these animals possess some innate and constant internal power, which determines them to act, in the same manner as when they are influenced by ordinary and accidental sensations. Instinct haunts them like a perpetual reverie or vision; and all the actions proceeding therefrom may be compared to those of a man walking in his sleep.

Instinct has been wisely bestowed upon animals by the Creator, to supply the defects of their understandings, the want of bodily force or fecundity; and thus the continuation of each species is secured to the proper extent.

There is no visible mark, in the conformation of an animal, by which we can ascertain the degree of instinct which it possesses. But so far as observation has hitherto extended, the degree of intelligence seems proportioned to the relative size of the brain, and especially of its hemispheres.

Without venturing to decide upon this point, we must remark that the latter assertion has been controverted by many recent observers, especially by Dr. Herbert Mayo, in his valuable Outlines of Human Physiology. "It does not appear," he remarks, "that an increase in the absolute weight of the brain confers a superiority in mental endowments. Were this the case, the intellects of the whale and of the elephant should excel the rational nature of man. Neither does the relative weight of the brain to the whole body appear the measure of mental superiority. The weight of the human brain is but one thirty-fifth part, while that of a canary bird is one-fourteenth part. Nor in conjunction with parity of form, and structure even, does this relation appear of any value. The eagle is probably as sagacious as the canary bird; but the weight of the brain is but one twohundred-and-sixtieth part of its entire weight.

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We may next inquire," he proceeds, "whether an increasing number and complication in the parts of the brain is essentially connected with improved mental functions. The first instances which occur to the mind are in favour of the affirmative of this supposition. It may be inferred, from their docility and surprising capability of receiving instruction, that birds have higher mental endowments than fish; and accordingly, in place of the nodules of the fishes' brain, which are scarcely more than tubercles to originate nerves, birds possess an ample cerebrum and cerebellum (or lobes of their brain). But in pursuing this argument, if we compare, on the other hand, the brain of birds with those of alligators and tortoises, we find no striking difference or physical superiority in the former over the latter; yet in mental development, the tortoise and alligator are probably much nearer to fish than to birds. The instantia crucis (or decisive experiment), however, upon this question, is found in the comparison of the brain of the cetaceous mammalia (such as whales or dolphins), with the human brain on the one hand, and with that of fish on the opposite. "The cetaceous mammalia," he observes, "have brains which, besides being of large size, are nearly as complicated as those of human beings; they might therefore be expected, if the opinion which I am combating were true, to manifest a remarkable and distinguishing degree of sagacity. Endowed with a brain approaching nearly in complexity and relative size to that of man, the dolphin should resemble in his habits one of the transformed personages in eastern fable, who continued to betray, under a brute disguise, his human endowments. Something there should be, very marked in his deportment, which should stamp his essential diversity from the fishes in whose general mould he is cast. His habits too, not shunning human society, render him especially open to observation; and the class of men who have the constant opportunity of watching his gambols in the deep, are famed for their credulity, and delight to believe in the mermaid, the sea snake, and the kraken. Yet the mariner sees nothing in the porpoise or the dolphin but a fish, nor distinguishes him except by his unwieldy bulk, from the shoal of herrings he pursues. The dolphin shows, in truth, no sagacity or instinct above the carp, or the trout, or the salmon. It is probable even that the latter, which have but the poorest rudiment of a brain, greatly exceed him in cunning and sagacity. I am afraid that the instance which I have last adduced is sufficient to overthrow most of the received opinions respecting the relation of the size, shape, and organization of the brain to mental development; nor is it easy to find a resting-place for conjecture upon this subject."

SECT. VIII. ON THE CLASSIFICATION OF THE ANIMAL KINGDOM.

General Distribution of the Animal Kingdom into Four Great Divisions.-1. Vertebrata2. Mollusca-3. Articulata—4. Radiata.

AFTER the observations which have already been made concerning systems of classi fication in general, we have now to ascertain those leading characters of animals, upon which we must found the primary divisions of the Animal Kingdom. It is evident that these must be derived from the animal functions, that is, from sensation and motion; for not only do these functions constitute them animals, but they point out the rank which they hold in the animal world.

Observation confirms the correctness of this reasoning, by showing that their development and intricacy of structure correspond in degree with those of the organs performing the vegetative functions.

The heart and the organs of circulation form a kind of centre for the vegetative functions, in the same manner as the brain and the trunk of the nervous system are the centres of the animal functions; for we see these two systems become gradually more imperfect, and finally disappear together. In the very lowest classes of animals, where nerves can no longer be discovered, all traces of muscular fibres are obliterated, and the organs of digestion are simply excavated in the uniform mass of their bodies. The vascular system [or systematic arrangement of vessels] in insects, disappears even before the nervous; but, in general, the medullary masses are dispersed in a degree corresponding to the agents of muscular motion. A spinal marrow, on which are various knots or ganglions, representing so many brains, corresponds exactly to a body divided into numerous annular [or ring-like] segments, supported upon pairs of limbs, distributed along its entire length.

This general agreement in the construction of animal bodies, resulting from the arrangement of their organs of motion, the distribution of the nervous masses, and the energy of the circulating system, ought, then, to form the basis of the primary divisions of the Animal Kingdom. We shall now proceed to examine what the characters are, which ought to succeed immediately to the above, and give rise to the first subdivisions.

If we divest ourselves of the popular prejudices in favour of long-established divisions, and consider the Animal Kingdom upon the principles already laid down, without reference to the size of the animals, their utility, the greater or less knowledge we may have of them, or to any of these accidental circumstances, but solely in reference to their organization and general nature, we shall find that there are four principal forms, or (if we may use the expression) four general plans, upon which all animals appear to have been modelled. The minor subdivisions, by whatever titles they may be ornamented by Naturalists, are merely slight modifications of these great divisions, founded upon the greater development or addition of some | parts, while the general plan remains essentially the same.

1. VERTEBRATA-Vertebrated Animals.

In the first of these forms, which is that of Man, and of the animals most resembling him, the brain and the principal trunk of the nervous system are enveloped in a bony covering, composed of the cranium [or skull], and the vertebræ [or bones of the neck, back, and loins]. To the sides of this medial column are attached the ribs, and the bones of the limbs, forming collectively the framework of the body. The muscles, in general, enclose the bones which they set in motion, and the viscera are contained within the head and trunk.

Animals possessed of this form are called Vertebrated Animals (Animalia vertebrata) [from their possessing a vertebral column or spine].

They are all supplied with red blood, a muscular heart, a mouth with two jaws, one being placed either above or before the other, distinct organs of sight, hearing, smell, and taste, in the cavities of the face, and never more than four limbs. The sexes are always separate, and the general distribution of the medullary masses, with the principal branches of the nervous system, are nearly the same in all.

Upon examining attentively each of the parts of this extensive division of animals, we shall always discover some analogy among them, even in species apparently the most removed from each other; and the leading features of one uniform plan may be traced from man to the lowest of the fishes.

The following are examples of Vertebrated Animals: Man, quadrupeds, whales, birds, serpents, frogs, tortoises, herrings, carps, &c.

2. MOLLUSCA-Molluscous Animals.

In the second form of animals we find no skeleton. The muscles are attached solely to the skin, which forms a soft envelop, capable of contracting in various ways.

In many species earthy lamina or plates, called shells, are secreted from the skin, and their position and manner of production are analogous to those of the mucous bodies. The nervous system is placed within this covering along with the viscera; and the former is composed of numerous scattered masses, connected by nervous filaments. The largest of these masses are placed upon the oesophagus, or gullet, and are distinguished by the term brain. Of the four senses which are confined to particular organs, we can discover traces only of taste and of sight, but the latter is very often found wanting. In only one family, however, there are exhibited the organs of hearing. We always find a complete circulating system, and particular organs for respiration. The functions of digestion and of secretion are performed in a manner very nearly as complicated as in the vertebrated animals.

Animals possessed of this second form are called Molluscous Animals (Animalia mollusca) [from the Latin, mollis, soft].

Although the general plan adopted in the organization of their external parts is not so uniform as in the vertebrated animals, yet, in so far as regards the internal structure and functions, there is at least an equal degree of mutual resemblance The cuttle-fish, oyster, slug, and garden-snail, are familiar instances of this class of animals. 3. ARTICULATA-Articulated Animals.

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The third form is that which may be observed in insects and worms. vous system consists of two long cords, extending the entire length of the intestinal canal, and dilated at intervals by various knots, or ganglions. The first of these knots, placed upon the œsophagus or gullet, and called the brain, is scarcely larger than any of the others, which may be found arranged along the intestinal canal. It communicates with the other ganglions by means of small filaments, or threads, which encircle the oesophagus like a necklace. The covering of their body is divided into a certain number of ring-like segments, by transverse folds, having their integuments sometimes hard, sometimes soft, but always with the muscles attached to the interior of the envelop. Their bodies have frequently articulated limbs attached to the sides, but they are also very frequently without any.

We shall assign the term Articulated Animals (Animalia articulata) to denote this numerous division, in which we first observe the transition from the circulating system in cylindrical vessels of the higher animals, to a mere nutrition, by imbibing or sucking in the alimentary substances; and the corresponding transition, from respiration through particular organs, to one performed by means of trachea, or aircells, dispersed throughout the body. The senses most strongly marked among them are those of taste and sight. One single family exhibits the organ of hearing. The jaws of the Articulated Animals are always lateral, but sometimes they are altogether wanting.

As instances of this form, we may mention the earth-worm, leech, crabs, lobsters, spiders, beetles, grasshoppers, and flies. From the circumstance of their coverings, or limbs, being divided, or jointed, they derive the name of " articulated," from the Latin articulus, a little joint.

4. RADIATA-Radiated Animals.

To the fourth and last form, which includes all the animals commonly called Zoophytes, may be assigned the name of Radiated Animals (Animalia radiata). In all the other classes the organs of motion and of sensation are arranged symmetrically on both sides of a medial line or axis; while the front and back are quite dissimilar. In this class, on the contrary, the organs of motion and of sensation are arranged like rays around a centre; and this is the case even when there are but two series, for then both faces are similar. They approach nearly to the uniform structure of plants; and we do not always perceive very distinct traces of a nervous system, nor of distinct organs for sensation. In some we can scarcely find any signs of a circulation. Their organs for respiration are almost always arranged on the external surface of their bodies. The greater number possess, for intestines, a simple bag or sac, with but one entrance; and the lowest families exhibit nothing but a kind of uniform pulp, endowed only with motion and sensation.