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sarily exposed to the hazard of destruction-and, if by accident any species should perish, or if by changes in the constitution of the globe it could no longer preserve or perpetuate its race, although the number of species would be lessened, and the harmony of created forms disturbed or diminished, the sum of organized atoms would not decrease; but the portion which the extinct races might have appropriated to their own maintenance, would be distributed among other tribes, that by their multiplication the equilibrium of life should be duly and perpetually maintained.

It would be easy, while pursuing this hypothesis, to indulge in many interesting and many amusing speculations. There can be no doubt that it was from opinions like these we are considering, that the metempsychosis of the ancient philosophers was derived. The fabulous transmigration of men into animals and plants, was the allegorical veil which, in the schools of antiquity, was thrown over the most profound investigations of the operations of nature. The fable was transmitted by poetry and tradition, when the philosophy was disregarded or forgotten. The unalterable relation between destruction and reproduction, was preserved by this perpetual transmutation of particles; and this continued succession of new forms, arising from the evident destruction and decomposition of those which had already lived, gave to poetry unbounded scope for its wild and romantic creations—while philosophy, supposed that to maintain the equilibrium between organized and unorganized bodies, their peculiar and specific particles or principles were not only indestructible, but incapable, respectively of being converted into each other's substance. For, if the power of life could endue inorganic particles with vitality, impregnate them with feeling, excite them to activity, and adapt them to the purposes of organization, then rocks might serve as nutriment for man, and the earth itself, instead of the living inhabitants of its surface might furnish food for the vegetable and animal kingdoms. But the rock which moulders appears.only to furnish materials for the formation of other rocks; and when organized forms decay, their particles change not into rock, but become, in their turn, the materials by which other organized forms are supported and preserved.

To these primordial elements of organized bodies, vitality is supposed to be inherent. It is the germinating principle which, in the fables of antiquity, is said to have brooded over the unformed masses of chaos—the spirit of God which moved over the surface of the waters. It was the first action of creative VOL. 11.—NO. 4.

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power; the first manifestation of divine benevolence. When light was awakened from its hidden and unknown, if not eternal repose, life was created and distributed to animate and decorate the scenes, gladdened by the beams of day. Lite was mingled in the air and in the waters; life was diffused over the surface of the material world; life may have been distributed far beyond the sphere of our observation-far beyond the range of our most adventurous speculations-but every where and in all cases, when submitted to the scrutiny of our senses, it has been modified by the organization it has been compelled to assume.

Hence has arisen another and more important inquiry. It has been questioned whether the forms of organized beings which we now behold, are those which were originally created, and have been continued permanent and unchanged; or whether organization has been progressive, modified, altered, improved, perfected by its own inherent power. This doctrine of progressive organization, including in its precincts the theory of spontaneous generation, often renewed and as often abandoned, has been revived at a very recent date, with all the aids of science, and in the most public school of Europe. It supposes that only the simplest forms of life were at first created, perhaps, only those atoms endued with vitality of which we have already spoken ; that by the fortuitous collision or juxta position of those atoms, some concatenation, some arrangement of living particles may be said to have commenced. That from this point, which may be considered as fortuitous, the series of living forms began, and their arrangement or organization has thenceforward been in a state of continual progression, extending as the wants, varying as the desires of each successive race or generation should direct its vital powers. That as the first accidental forms would almost necessarily be irregular, the force of the vital power or nervous influence as it has been termed, would be directed to remedy the imperfections, or to improve the advantages of this primitive organization-and every irregularity in the primitive form would, probably, lead to permanent variations in the future structure. From this constant effort in the rude products of spontaneous generation to improve each its own structure, was fashioned by long and gradual progression, the more perfect forms we now behold. New members or new organs have been developed as new wants were felt. Thus for instance, to adopt the illustration of La Marck, if an animal like a slug or snail, which had acquired sufficient power to crawl on the surface of the ground, should still feel strongly the want of monitory organs, by which, when in motion it could feel the objects opposed to its progress; by directing the nervous

influence or power of its system to the anterior circumference of its body, it would gradually cause the extension or prolongation of some projecting points, until feelers, such as these animals now possess, should be insensibly but perfectly formed. In like manner, different organs have been fashioned for different animals, as their original outline or imperfect structure rendered necessary, and the accessions and variations to the form of each individual or race, bave been transmitted to its posterity.

This theory is in many points visionary, in some incongruous if not absurd. It would be difficult, even on its own principles, to account for much of the peculiar organization which the study of natural history discloses; or to assign final or operating causes sufficiently powerful for the production of many of the anomalous forms which the vegetable and animal kingdoms abundantly exhibit. We know not why there should be so much symmetry in each individual form, or why a few general plans should be made to comprehend all existing beings, while the species which are embraced in each plan, which may be said to surround each system of life, vary in almost endless diversity, but still preserve the fundamental arrangements of the system to which they belong. We find order where we would have expected inextricable confusion. And often we find organs so imperfect, that we might suppose this great work of progressive amelioration had been at some period suddenly arrested. We might for instance, inquire why, of the testaceous molluscæ, some of which have been adduced by La Marck as illustrations of his theory, should only a portion have acquired feelers? Has the age of the world not yet been sufficiently protracted-or why should not these feelers, which have been acquired in their march of improvement, have gradually been divided and thus fashioned into hands, and, finally, rendered capable not only of touching but of holding any object, facilitating by this means not only the acquisition of food, but the movements of the animal itself. If this power really belongs to life, to spontaneous life, it is surprising that so many of the inferior orders of the animal kingdom should remain condemned to a stationary and almost vegetative existence. Strange that there should have been a pause in this march of voluntary creation; a suspension of this power of progressive organization.

More powerful objections still occur. This progression of organization has apparently ceased, and we know not when or by what law it has been limited. If animals, furnished with the simplest rudiments of organization, have had power to multiply and complicate those rudiinents ; if the weakest combination of organs have bad energy enough to strengthen and

increase their structure, why should not the complex extend their combinations, why should not the strong acquire new powers? If the imperfect molluscæ by their continued desires and efforts to move and touch surrounding objects, could form new organs, why cannot more perfect man add to his stature or improve his structure? If the aspirations of an individual, or the efforts of numbers could avail, many, besides Dædalus, would have endeavoured to annex to their frames the pinions of a bird. And on the coasts of Ceylon and Coromandel, where occupations are hereditary and permanent, and where families, perhaps tribes, have for upwards of three thousand years pursued, from father to sou, the avocation of fishers of pearl; when the pursuits, the wealth, the anxious desires of these people all lay beneath the waves, surely in this long term of years, some races might have acquired some portions of the organization of the fish.

Even this, however, is an imperfect view of this question. If every organized body had advanced in the scale of organization to a somewhat equal degree; if all, though moving in different directions, had reached the circumference, the common boundary of some great circle, it might be supposed, that while the power of progressive organization had been granted as an attribute of life, and each individual or race been left to determine by accident the extension and direction of his own organs,

there had yet been placed, from causes inscrutable to us, some limit to the progress, some ultimate term to the improvement of or ganized life. But such has not been the history or the march of creation. We discover, even now, forms as imperfect, structure as incomplete, organization as simple as could apparently ever have existed. From the Monas Termes, the point where voluntary motion and life appear to our view to commence, the lowest term in our scale of sentient being, to man himself, we perceive the intermediate degrees occupied by a vast variety of forms, by almost unappreciable grades of organized substances, and yet in all of these substances or beings, this power of progressive organization, has long been suspended. It is upwards of three thousand years since accurate descriptions of some portions of the animal kingdom have been transmitted to us, and in that time, none of those objects which have been described, have undergone mutation. The camel and the horse are now as in the days of the patriarchs. Can the leopard change his spots? was asked many ages ago, and the leopard has not yet changed his spots, nor the Ethiopian his skin. And yet it may be remarked, that peculiarities of colour are among the most variable and fugitive properties of organized bodies.

There was a period, whilst science was yet undisciplined, when the minute microscopic animals were supposed to afford a strong support to this doctrine. They were asserted by many and admitted by more to be the products of an unintelligible spontaneous generation, the offspring of heat, of moisture, of the fermentation of elements endued with vitality, or of causes still more obscure. But in proportion as these bodies have been examined, under the guidance of an accurate and cautious pbilosopby, the darkness which overhung their origin has been dissipated. Forms the most minute, animals visible only under the lens of a compound or solar microscope, are found to have their structure as complete, the laws of their production as definite, their metamorphoses as regular as those of organized bodies, apparently the most perfect. Knowledge bas swept away most of these illusions among the errors of unenlightened ages, and although myriads of animated beings are so minute as to elude the power and observation of our most perfect instruments, shall we not conclude that the plan, the system, which governs so beautifully, so uniformly, the kingdom of the living until our scrutiny ceases, because the eye fails us, must, on every principle of analogy, extend also to those far confines of nature that are to us invisible.

These opinions have, in some measure, been supported by the fact that animal or vegetable substances hermetically inclosed, and then subjected to degrees of cold or heat, sufficient to destroy, according to our observations, every germinating principle, every vestige of life, have yet been found after some time to contain living forms in wonderful abundance. Many solutions, however, may be given to this difficulty. We, ourselves, see imperfectly. Our powers of vision and of observation are very limited, and in our experiments, we are attempting to exclude by the coarse materials adapted to our senses and our instruments, beings to whom the most compact metals may appear like open net-work, and the diamond as porous as a honey-comb. Besides, we may miscalculate the power of heat or cold on life, because to some grades they are found pernicious. For when we perceive how wonderfully the Creator has prepared the races that surround us to live in differing elements, in air, in water, in the earth; how can we limit his power or his beneficence, how avoid the conclusion that forms might be fashioned to breathe even the pure ether of the empyrean space, or bask in the unclouded blaze of elemental fire ?

One fact, however, connected with this discussion, we cannot omit to notice. When we examine the now existing forms, and compare them with the remains of the extinct races which are

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