Monday, 2 March 2015

THE THEORY OF DEVELOPMENT

MR R. D. HANSON'S LECTURE ON THE THEORY OF DEVELOPMENT.

We have great pleasure in fulfilling our promise of presenting to our readers a copy of Mr Hanson's admirable Lecture on "The Theory of Development, as illustrative of the History of Creation," delivered last week at the quarterly conversazione of the South Australian Library and Mechanics' Institute.
 In the history of the progress of the human intellect, no one fact is perhaps more noticeable than the gradual recognition among mankind of the idea of law as regulating all the phenomena of Nature, even those which appear at first sight, the most capricious and exceptional. The first impression produced upon the observers of Nature, by the almost infinite variety of natural appearances, their seemingly arbitrary succession, and confused intermingling, appears to have been one of bewilderment. No clue existed as a guide through the labyrinth, and accordingly the earliest thinkers seem not merely to have assumed separate causes for each individual phenomenon, but to have referred every manifestation of power to supernatural influences. The growth of trees, the flowing of rivers, the flux and reflux of ocean, the courses of the winds, the succession of day and night, thunder, lightning, and tempest, were referred to the immediate interposition of spirits—demons, as they were termed. The earth itself, from which all beings derived their sustenance, was a goddess, the mother of all living ; the sun, whose vivifying influence awakened Nature from her wintry sleep, quickened vegetation, and matured the products of the soil, was a god. Something like this, so far as we are able to trace, is found at the beginning of all systems of thought ; though in the East, the idea of unity which characterizes their early speculations caused these powers to be regarded as emanations from the Supreme Deity, and among the nations of the West they were regarded as independent beings. Gradually, as experience became wider and the results of observation were recorded, a certain regularity was found to characterize these phenomena, and they were successively reduced under what are termed laws, and which mean a general expression which combines within it all the observed particulars of a certain class. Thus we talk of the law of gravitation, of the law of electrical attraction and repulsion, of the law of proportion as applied to chemical combinations, and others as applied to external objects, and of the laws of association, &c., as applied to our intellectual nature—meaning that, in reference to all these matters, there is a certain definite order or sequence in the occurrence of phenomena which may be included under one general formula. The phenomena of the heavenly bodies appear to have been the first in which the existence of these laws was perceived, and the observation of the recurrence at certain regular intervals of the same phenomena, gave birth to the science of astronomy. And this was followed by others, until the accumulated experience of the human race has succeeded in bringing almost every occurrence within the range of some one or other of these laws, so that scarcely anything in the physical, intellectual, or moral world, can now be considered as exceptional. And even with regard to those few seeming exceptions which still remain, we may reasonably anticipate that they also, in time, will find their appropriate place in the great scheme, so that nothing will remain anomalous or irregular. I may however observe, that the discovery of these laws implies no progress whatever in our knowledge of the ultimate causes of observed appearances. We have learned in what order and mode phenomena occur, but we are as far as ever from ascertaining why this takes place. We know, for instance, that a seed grows under certain conditions of heat and moisture ; that chemical agencies are thus set in motion which enable the embryo to develop itself and to derive nutriment, first from the matter of the seed itself, and then from the earth ; but why these circumstances should produce such a result we do not know. So it is, and so it has been, and therefore we assume that so it will continue to be ; and we find the rules thus deduced adequate to all practical requirements. But why a plant should produce a seed, why the seed should have just such an organization as fits it for these influences and enables it to rise into a seed producing plant itself, is a matter as yet utterly beyond the range of our knowledge.
 It is one of the conditions of our mental constitution to seek for order in apparent confusion. and to attempt to educe simple laws from the most complicated phenomena. The advantages of this are numerous and apparent ; but one result has been the formation of innumerable crude theories, which have had the twofold weakness of attempting to carry speculation beyond the limits of human faculties and of deducing laws from an insufficient induction of facts. And perhaps no single topic has been more fruitful in these theories than that which concerns the original formation and arrangement of matter, and which has been termed the natural history of creation. From the days of Anaximander, the father of Western philosophy, who deduced all being from moisture as its original cause, down to the latest speculators, this has been a favourite topic ; perhaps because its very vastness and vagueness tempted speculation and gave ample scope to theory. Did our time permit, it would be an amusing and not ininstructive subject to go through these different speculations—one deriving all things from heat as the primal cause ; another seeking it in harmony or proportion ; and another in a fortuitous combination of atoms. We may however, in passing, just notice the speculations of Buffon, who supposed that the earth and the other planets which constitute our system had been struck off from the sun by a succession of erratic comets, with forces just proportioned to the slice they were to strike off and the distance to which they were to impel it—a speculation which has been happily characterized by Byron, who speaks of

"A wild colt of a comet, which too soon 
 Broke out of bounds across the ethereal blue,
 Splitting some planet with its playful tail,
Just as a boat is severed by a whale."

 The last, however, and the most philosophical of these theories, is what is termed the nebular theory, propounded in the first instance by Herschel, and brought within the range of mathematical expression by Laplace and Lagrange, and which has obtained a very wide assent among astronomers. Some brief notice of this will appropriately introduce the more immediate subject of the present lecture.
 It was found by Herschel that there were certain bodies in the heavens which were visible to the naked eye, or with telescopes of very inferior power, and then had a white cloudy or nebulous appearance, which, although subjected to the highest powers of the telescope, never assumed any other aspect. Their apparent dimensions were increased, their external form changed, but still they always seemed as a light filmy cloud : while at the same time others, similar in their first appearance, and which required very high powers of the telescope to indicate their existence, were easily resolvable into separate stars. He also observed many gradations in the appearance of these ; some seeming to indicate condensation in one or more parts of their body, as though these formed centres to which this nebulous matter was attracted, and others passing through various forms until they assumed the appearance of a star surrounded with a faint nebulous haze. From this and from other phenomena he was led to conjecture, and to propound as an hypothesis, that all the stars and their planets had originally existed in this nebulous form, their constituent parts being volatilized by intense heat ; and that, under the influence of the attraction of gravitation, accompanied by a slow diminution of heat, they had gradually become condensed into planets and suns. Others who followed him showed that this might occur strictly according to the laws of gravitation in such a manner as to produce all the observed phenomena of the rotation of the planets upon their axes and their revolution round the sun ; and the theory was strengthened by appearances in our globe which led to the supposition that the earth had, at one time, possessed a far higher temperature than at present, and that it might have been and probably was originally in a state of fluidity. The hypothesis, therefore, as it explained many observed appearances, and seemed accordant with known laws, received general acceptance, though always propounded as a theory which further observation might confirm or disprove. This theory, however, applied only to the inorganic constituents of the globe, and was not supposed to give any explanation of the origin of organic life upon its surface, any more than it would account for the first existence of the supposed nebulous matter itself, or for the laws to whose operation it owed its ultimate form. It would explain creation in the same manner, but in no other, as the existence of a seed of any particular plant, and of the natural laws to which that seed owes its growth, would explain the appearance of the plant which sprang from it. A theory, however, was wanting which might bring within the range of some law the origin and present phenomena of organic, in the same manner as this was supposed to have given an explanation of the form and constitution of inorganic matter. And it is such a theory that I propose to-night to examine.
 One of the first things that strikes an observer of nature is the appearance of progression in organized structure. Thus—from the simplest form of vegetable life up to the most mighty and elaborate ; from the fungus, which can scarcely be distinguished from the stone on which it grows, up to the oak, the monarch of European forests, or the loftier forms of vegetable life which are found within the tropics— there is a series easily traced, proceeding by almost imperceptible gradations and with no violent break. And in the same manner, from the simplest forms of animal life, where the naturalist is barely enabled to discern whether the mass before him belongs in reality to the animal or the vegetable kingdom, up to man, the most perfect type in his physical organization of animal existence, there is the same progressive development. All proceeds by gradation, and though sometimes a link in the chain is missing, this is an unfrequent exception to a well established rule.
   This is a fact which suggests itself to a merely superficial observer ; but when comparative anatomy began to attain the rank of a science, it was found that this gradation was more real than had been at first imagined, and that the resemblance between different species extended to points where, at first sight, there was the greatest apparent distance. Thus, for instance, it was found that, in mammalia, there is a surprising uniformity of structure where the external form shows the greatest diversity. The number of joints in the neck, for instance, is in almost every instance uniform. The cameleopard has no more bones in the neck than the hog or the elephant—though in the former the neck is long and flexible, and in the latter there appears almost to be no neck at all. So in the bones of the arm and hand of man, where those are most developed, there are the same number of bones in the leg and hoof of the horse and of the elephant ; and what is still more unexpected, in those of the mammalia which live in the water—as the whale and the porpoise—their fore-fin contains the same number of bones similarly arranged ; and in those of the same class which seek their food in the air—as the different tribes of bats— there is the same adherence to the type, since the membrane which serves the purpose of a wing is stretched upon an extension of the forefinger. In fact, the law of the animal organization appears to be, that all animals of the same class are formed upon one type—which is preserved in all cases in which a departure from it is not necessitated by the conditions imposed by the intended mode of life of the animal. Nothing is done arbitrarily. The discoveries of geology, too, show similar results, with this additional circumstance, that, allowing for exceptions which may possibly admit of explanation from the destruction of many of the earlier forms of being, on account of their not being fitted to resist the various causes of decay to which they have been exposed, the simplest and humblest are the earliest. In those rocks which are known to have been first deposited, the remains discovered consist almost entirely of shellfish. In the succeeding formations, there is a gradual advance to higher forms of being—to fishes, reptiles, birds, and mammalia, beginning generally with the lowest classes of each— until in that era which appears to have immediately preceded the present arrangement of the earth, we find remains of the representatives of almost every family now existing, excepting the sheep and the goat, and man. It would be needless for our present purpose to examine all these matters in detail, and to show to what extent the line of progress in the appearance of organic being upon the world is preserved, and in what instances it is violated. It would require a minuteness of illustration to which your time and my knowledge are equally inadequate ; and since the general fact is indisputable, any apparent or real exception would be easily evaded or explained away by those who have a theory to support.
 There are thus three classes of facts applicable to this subject, which we may take as ascertained. First—that, in the existing forms of being, there is a gradual progress from the simplest to the highest organization—the development of organ and of function proceeding by slight gradations. Secondly—that, even in the greatest seeming differences, there is reference to an uniform type upon which all classes appear to have been formed. And thirdly—that the appearance of animal and vegetable life upon the globe appears to have been to a considerable extent, if not altogether, in the same order of progress. These facts form the materials from which different individuals have from time to time endeavoured to construct a natural history of creation.
 One of the first who attempted to deduce a theory from these facts was Lamarck—for we may pass over the speculations of Munthodds,[Mondobbo?] who derived the human race from a family of apes, who, getting rid of their tails, and by some undescribed process turning their hind hands into feet, continued to acquire reason and language, and the ideas of morals and religion. The theory of Lamarck was, in substance, that all organised beings began from the simplest forms, by the constant operation of certain tendencies in the animal—that, for instance, a soft-shelled mollusk, finding the necessity of some covering to protect it from its numerous enemies, began to endeavour to form a shelly covering, and, by continuing these efforts through many generations, arrived at length at the safety and dignity of an oyster ; that others, directing their labours in a different path, became mussels—others, limpets ; that others again, with different tastes, found that the vegetable food to which their original organization condemned them was insipid and monotonous, and, by dint of striving, they also attained arms to seize, a mouth to devour, and a stomach to digest animal prey. That then some, favourably circumstanced, attained a considerable bulk, which rendered it inconvenient to be confined to one spot, or to be without the means of rapid motion, and that, by constant efforts, they changed their soft substance into the firmer flesh of a fish, furnished themselves with a back-bone as a support for the muscles, with fins and a tail as instruments of progression, and elongated their form into that most convenient for freedom and rapidity of motion. In this manner, they proceeded from one grade to another, until they had arrived at the form of the seal or sea-lion, whose habits are amphibious ; that then one of these, more ambitious or more inventive than his fellows, conceived the idea of legs, and incontinently set himself to work to desire and strive after them. Gradually, he acquired them, and passed into some other form—such as the hippopotamus or the otter—retaining something of his amphibious habits, and seeking generally the same species of food to which he had been previously accustomed. In the same manner, we are to imagine these amphibious beings, pushed by necessity arising from scarcity of food in their accustomed haunts, or driven forth by their companions from their society, or impelled it may be by a mere love of variety, leaving their aquatic domain, and seeking food and shelter in the meadow or the forest, and then transmitting their newly acquired desires to their offspring, who in the course of successive generations—each making some step in the process—acquired the organization suited to their new position. In this way we are to suppose that all the various species of animals were gradually produced. The camelleopard, in this view, would be the descendant of some nameless progenitor, who, straying by chance into the arid regions which border upon the African deserts, and finding that no small portion of his food was only to be procured from the branches of trees, taller them himself, by dint of stretching towards them, and constantly endeavouring to raise itself, in process of time succeeded in lengthening his neck and his shoulders. The elephant we are to suppose to be descended from some animal who sought the same end by different means, and instead of lengthening his neck—which, considering the great weight of his head, would have been a perilous attempt—contented himself with lengthening his nose, and succeeded in elongating it into a trunk. Having accomplished this feat, it was discovered that something was needed as a lever to assist in loosening the roots of trees which were still too high to be reached with the trunk, in order that they might be easily overthrown, and for this purpose the tusks were pushed out ; and we might go on with the same reasoning, and suppose that, at the same time, it enlarged its ears for the sake of ornament, and shortened its tail in order to keep it out of the reach of tigers. This sounds very ridiculous, and it really is so ; and the absurdity of the doctrine, as originally propounded, has led to its abandonment by every one with any pretension to accurate knowledge or enlarged views. It must not, however, be supposed that it appeared to be quite as absurd in the pages of its author. On the contrary, it was put forward in a form which made it really plausible. Those facts which might appear to yield support to the theory were paraded in front ; whilst those which were irreconcileable were carefully left out of sight. A little colouring, and a great deal of imagination—some sophistry, and much eloquence were employed to give shape and consistence to the theory ; and, for the moment, it appeared not merely novel and ingenious, but to have some foundation in truth. The difficulties with which it was surrounded were, however, insurmountable; and for some time it has scarcely been referred to, excepting as an example of the absurdities into which even profound investigators of nature may be led in the pursuit of a favourite theory.
  Within the last few years, however, another theory of development has been propounded in a book which has obtained a very high degree of celebrity in England, called the "Vestiges of Creation." This theory I propose now very briefly to examine, not in its details, but in its principles. The theory itself may be concisely stated, and I will endeavour to do this completely and fairly.
 It begins with the nebular hypothesis which I have already noticed, and supposes that all matter existed at first in the form of a diffused nebulosity—that there was sufficient heat to vapourize the most solid substances, and that, in this nebulous or gaseous form, the matter of which the different bodies of the solar system was composed, stretched infinitely beyond the present limits of the orbit of the most distant planet. It is further supposed that this matter was created, and that it was endowed by its Creator with certain electrical, chemical, and vital affinities and powers. That by the influence of gravitation it became in the course of ages condensed into planets and their satellites and the remnant of it finally into the sun. That in the first state of our planet, everything was in a state of fusion, and consequently unfit for the development of animal or vegetable life ; but that, as it became cooled down, and as the combined operation of the air in decomposing the substance of the primitive globe, and of water in washing away the separated particles, and accumulating them at lower levels, produced their effect, the inorganic elements, operated upon by the influence of heat and electricity, began to develop organic forms, which were, by force of their organization, endowed with life. It is not argued that this took place by virtue of any power necessarily inherent in matter itself, but in consequence of and in obedience to laws impressed upon it by its Creator in the moment of its creation ; so that this development of life was as much the act of the Deity as the subjection of matter to the laws of gravitation, and of chemical and electrical attraction. That the forms which were first produced were the lowest and simplest both of the animal and vegetable world—not merely as being best adapted to the existing condition of the earth, but in obedience to that law of progress which is assumed to be the ruling principle of the universe. That these forms gradually passed into others more elaborate in structure and with superior functions—and thus, not from the act of the animals themselves but in obedience to a law of their organization as irresistible as that which leads them from infancy to maturity, and from maturity to decay, the very highest forms were ultimately obtained. This is in substance the doctrine of Lamarck, to which I have already adverted ; but differs in many points of detail, and in two main principles. In the first place, in obedience to the religious sentiments of the day, it attributes all the changes to the creative fiat, and professes to assume that every step in the progress was designed and provided for by the Deity ; and in the second place, instead of supposing a gradual change in the individual, by which the fish which had been born an inhabitant of the water became a denizen of dry land, it assumes that the change took place in the embryo—so that, from the egg of a fish a reptile or a mammal might be produced, and from the egg of a reptile a bird ; that the offspring of an aquatic mammal, such as the whale or the seal, might prove a quadruped ; and then that by the influence of external circumstances modifying organization, assisted by the efforts of the individual, the different forms of quadrupeds within certain limits might be produced from one type. Thus, he supposes, or rather, puts forward as possible illustrations of his views—that from the seal, the sea-lion, and the other fish like mammalia who live by prey, the different predatory quadrupeds derive their origin. The bear, for instance, is derived from the seal, and becoming in its turn the progenitor of the dog, the wolf, the hyæna, the jackal, &c. That from another class which fed on vegetables, the different varieties of the ox family, and through them all the ruminating animals, such as the stag, the goat, and the sheep, derived their origin. That the horse and other allied races spring from a third class, and so on. In this genealogy, it is of course incumbent upon the author to find a parentage for the human race ; and he has done this, but in a manner to excite some surprise, and certainly calculated to give rise to not a little ridicule. He derives mankind from a race of frogs! In one of the earlier formations traces have been discovered of the footsteps of a gigantic frog, supposed have been upwards of four feet in height ; and this animal, of which no other vestiges remain, unless it be a few doubtful teeth, is invested with the dignity of fatherhood to the human race. Of course there must have been intermediate stages, but these are not distinctly marked out, though the leaning of the author appears to be to acquiesce in the common theory of his predecessors in this path of speculation, and to suppose that the ape is our immediate progenitor. How frogs should be transmuted into apes, and how apes should be elevated into men, is of course left to conjecture ; but in spite of the difficulties of explaining the manner in which the process has been accomplished, it is clear that we are to consider the whole tribe of monkeys as our half-brothers, and the family of frogs as our cousin-germans ; and we are to see in this relationship a proof of the wisdom and dignity of God. The author of the theory I am noticing says, "In these things the superficial thinker will only see matter of ridicule. The large-hearted and truly devout man, who puts nothing of nature away from him, will on the contrary discover in them interesting traces of the ways of God to man, and a deeper breathing of the lesson, that whatever lives to him is kindred." I have no space to expose the fallacy, and what I can only designate as the "cant" of this sentimentalism. I must content myself with observing that I should doubt if many of my hearers are large-hearted enough to acquiesce in this conclusion.
 This is necessarily an incomplete view of the theory of development ; but it is, I believe, accurate as far as it goes ; and I have endeavoured to make it impartial. I purpose now to consider shortly the arguments by which it is supported.
 It would be admitted by the supporters of this theory, that there is no proof of any such transmutation of species as they here assume. It is not pretended that any examples can be found, either within the period of history during which observations have been recorded, or in the relics of former races which have been discovered among the strata of the globe. The theory is put forward simply as an hypothesis—as a means of bringing the whole phenomena of the appearance upon our world of successive forms of being, and the phenomena which characterize the existing races, under one law which shall suffice to account for and explain them. But it is argued that, from the nature of the case, such proof cannot be expected—that it may be assumed that man is the completion of the scheme, and that, with his appearance on the stage of the world, the formation of new species would naturally cease ; so that the permanence of species during the few thousand years of which we have records, forms no ground for denying the fact of their transmutation previously to that epoch. And that, with regard to the fossil remains of extinct plants and animals, it is impossible to say whether a new species is a new creation, or whether it may not have been derived by descent from older and simpler forms of being. It is thus argued, that inasmuch as there appears reason to conclude that the arrangement of the world—the formation and superposition of strata—the distribution of land and water, and every thing which fits the surface of the earth and the depths of the waters to be the support and the home of organic beings, is the result of the simple operation of natural laws ; of gravitation, of chemical affinity, of electrical and magnetic forces ; and, as the appearance of the earliest forms of life it a phenomenon occurring in the order of progress, and essential to the completion of the apparent scheme of the world, there is no necessity for supposing that for so trifling a change any direct interposition of creative power is necessary. That, on the contrary, it enlarges our idea of the power and wisdom of the Deity to suppose that everything was planned from the beginning, and that the machine of the universe, once being set in motion, continued to act, and to evolve from its own substance, in obedience to the laws to which it was originally subject, all the forms which were intended to fill up the plan of creation as it existed in the mind of its Author. And that it is derogatory to our conception of the Deity to suppose a specific intervention every time that a new species of snails, or insects, or reptiles, was to make its appearance upon the earth. It is then argued that the progressive character of fossil plants and animals is consistent with the supposition, that the more complicated were derived from the simpler forms ; and it is asserted that it is not to be explained upon any other hypothesis, since there was nothing in the condition of the world for countless ages before the first appearance of man, which could have rendered it unsuitable for the dwelling place of the human race. And finally, the fact of the uniformity of structure in different species to which I have already adverted is referred to as giving support to the hypothesis, since it is asserted that this is only to be explained upon the assumption of a common parentage.
The first point to be noticed in reference to this train of argument is not unimportant. It is that, however the hypothesis may serve as an explanation of the appearances for which it is designed to account, it cannot be made the basis of any argument beyond the precise limit of their appearances. It is purely a speculation, which, however plausible, has no certain basis in fact. As an exercise of ingenuity, or as gratifying curiosity, it may be entered upon or accepted by any one ; but it affords no foundation for any inference as to the present or the future. If, for instance, any one were to argue from this, that, by a reverse process to that which is assumed to have operated to evolve mankind from monkeys immediately, and from frogs remotely, any portion of the human race could be degraded into apes or frogs ; or that the future destiny of man was the same as that of the apes and frogs, from which it is assumed he sprang ; or that the Creator, like the gods of Epicurus, sat an idle spectator of the world he had formed, and left everything to go on by chance, or by law, which is here another word for chance : he would not merely be foolish, but illogical—since he would be reasoning from that as a fact which is confessedly only an hypothesis. Practically, therefore, the theory is barren, and until it can be raised from a theory into a law, by distinct and incontrovertible evidence, it can effect no practical results. This remark would be needless, were it not that these theories are seldom originated simply for the sake of the theory itself, but generally, if not always, with reference to some ulterior object. Now the rule for the human understanding to pursue in all similar cases is : when a law is established, to investigate all its consequences, and to accept them so far as they are shown to be legitimately derived from it ; but when an hypothesis is propounded, to investigate its evidence, without any consideration of consequences, and rigidly to reject them until the truth of the hypothesis is demonstrated.
 Looking at this theory, then, simply as an hypothesis, the first objection is, that it proceeds upon an assumption for which there is no warrant in the observed appearances of nature. There is no instance of any such change as that which is assumed as the foundation of the argument. That a fish should change into a reptile ; or a reptile into a bird ; or a fish into a mammal ; or an aquatic bird into a land bird ; or a whale into an elephant—implies something not merely unsupported by proof, but at variance with experience. And the instance given, the only instance so far as I am aware of such a transformation, instead of showing the possibility of such transformations, is decidedly opposed to their occurrence. I allude to the case of the frog, which, as all of my hearers are probably aware, commences life as a tadpole : having fins, gills, and a tail, all of which are wanting in the mature animal, and only fitted to live in water, while the frog is amphibious. But in this case it is found that, upon dissecting the tadpole, the perfect form of the frog is enveloped in it, so that the perfect reptile is present, though undeveloped, in the humbler form through which it at first passes, in the same manner as the butterfly is present in the caterpillar from which it springs. It is urged that the development of the frog may be prevented by keeping the tadpole in a dark box in the bottom of a stream, without access to light or air ; but in this case the reproductive power of the animal is undeveloped—no perfect animal, even of the fish kind, is produced—and the tadpole, though increasing in size, dies without continuing its species. The accounts given of the production of insects by means of electricity, assuming them to be true, and it is my purpose in the present lecture not to dispute facts, or alleged facts, but to investigate arguments—prove nothing in this case. They might show that all animals are formed from matter, by some intermediate process, instead of immediately by creative fiat ; but they prove nothing in favour of the theory which we are now examining. In the first place the animals alleged to be produced are not at the lowest point of the scale, since they are animals with limbs, and propagating their species by eggs ; and therefore not such as, according to the hypothesis, should first make their appearance from the elementary substance ; and in the second place there is no ground given in these experiments for supposing that those crawling creatures could by any process of development form whales or elephants. I should perhaps say in reference to this, that I suspect there is some undetected source of error in these experiments, because, if they are rightly described, the sub- stance of these animals is not present in the acids, &c., from which they are supposed to be formed ; and I cannot ascribe to electricity any absolute creative power. I say this, not as doubting the good faith of those who have made the experiments referred to, but because we know the fallacy of experiments of this nature, and in how many instances a more accurate and careful repetition of the process has disclosed some unsuspected source of error ; and it seems more philosophical at least to suspend the belief until there is such an accumulation of evidence as to render doubt impossible.
 But we may go further upon this point. The supposed progression of species by the transmutation of individuals into higher forms is not merely unwarranted by the observed process of nature, but it is supported by no sound analogy. The old theory of Lamarck, to which I have adverted, had something like analogy upon which to rest, since we do see certain changes both in vegetables and animals, resulting from modes of culture and from the influence of climate and food. The numerous varieties of garden flowers—the rose, dahlia, and innumerable others have been so far changed in some of their characteristics, that it is almost difficult to believe in their identity with the original stock. It is the same with vegetables. The different varieties of the cabbage tribe, all of which are supposed, and apparently upon good grounds, to be derived from the same origin, and to have been varied by culture, afford a more striking instance, because not merely the flower, but the whole appearance, and in many respects the qualities of the plant are changed. And in the humbler species of plants there are instances in which a change of soil and circumstances, as from a dry to a marshy position, or the reverse, occasions so great an alteration, that experienced botanists have for a time been deceived, and have at first, and sometimes for a considerable period, imagined them to be distinct species. In animals also, the numerous varieties of the sheep, the goat, and the ox species, of the horse and of the dog, all of which, with the exception perhaps of the latter, are supposed to be nothing more than variations, resulting from the influence of external circumstances, show the same power of change. There was therefore, apparently, some ground for the argument, that changes from one species to another nearly allied, might take place, in consequence of the constant exposure to influences adapted to produce such a change. But the answer to this is, that all of the changes which we are able to produce, or which we witness as produced around us, are confined within certain definite limits. It is possible to increase the size of a plant, to alter the colour of its flowers, to change single flowers into double ; or with animals, to breed them for size, or for swiftness, or for the fleece, or for any purpose which may suit the interest or the caprice of their owners ; but no art with which we are acquainted could transform the cabbage into an oak ; and after all that is done, the sheep, or the horse, or the ox, remain a sheep, and a horse, and an ox still. And it is invariably found that, so soon as they are withdrawn from the influence of those circumstances which have modified their organization, they revert to their original type. There is, so to speak, a certain elasticity of constitution, with which all organized beings endowed, and which is needed in order to enable the plant or the animal to accommodate itself to new circumtances, and without which every species would be exposed to the risk of extinction at every change of condition ; but this power of accommodation is confined within limits prescribed by the original organization, and cannot in any case be made to overpass these natural boundaries. This ground of analogy, however, is admitted by the supporters of the theory we are considering to be inadequate for the explanation of the really difficult part of the assumed process. They admit—for after all that has been written on the subject, it would be ridiculous to attempt to controvert the position— that no animal can by any effort of its own effect such a change as from a fish to a reptile, or from a reptile to a bird ; and therefore they are compelled to have recourse to some occult power, which, working in the embryo, where the influence of external circumstances is included—causes the production of an albatross from the egg of a turtle ; or of a turtle from the egg of a fish. Now, in support of this figment of the imagination, there is no basis of analogy whatever. It is a gratuitous assumption ; and it is difficult to imagine any other motive for it than the desire, from whatever motive, of excluding all idea of the intervention of the Deity since the creation of the original chaos. I know it may be said in reply to this, that they recognize the Deity as the author of the law which causes this apparently anomalous result. But the Deity, as they feign him, is nothing but the inexorable fate which the ancients imagined—a mere personification of natural laws, which is to work blindly and inflexibly ; or at best a Being, who, having at first set the machine in motion, retires for ever from the universe which he has originated. I have no wish, in any of these remarks, to create a prejudice against the hypothesis, to limit inquiry, or to fetter speculation. I know that the probable result of any attempts to clog the pursuits of science, lest they should clash with the dogmas of theology, would be to give us at once an unsound science and an uncertain religion. But we have a right to arraign an hypothesis, which, even upon the showing of its supporters, is manifestly baseless, if it clashes with what we believe to be true on other grounds.
 I have said that this idea of changes taking place in the embryo, where there can be no influence from external circumstances, has no foundation, even in analogy ; but perhaps I ought not to pass over, without notice, the grounds upon which it has been suggested. It is alleged that the embryo of all beings passes through different stages—that, for instance, in the egg of a bird, there is a time when the incipient animal has a worm-like appearance, and is analogous to the type of invertebrate animals ; that, afterwards, as its development proceeds it assumes a form analogous to the fishy type, then to the type of a reptile, and finally to that of a bird ; and that, in the foetus of mammalia, the embryo undergoes all the same changes, including that of the bird embryo, until it assumes the form of its more elevated type ; and then, it is said, we have only to imagine that in obedience to some occult law of its organization, the process of development in the embryo is carried forward another stage, and then the production of a young animal of a higher class is explained. When, however, the question is asked—Why should we imagine this? no answer, as far as I am aware, is attempted to be given. If it could be said that the imperfect embryo of one of the mammalia, which from some cause or other was arrested in its development, came forth as a perfect bird ; or, if arrested at an earlier stage, came forth as a reptile or a fish—then there would be something like a ground of argument, however shadowy and evanescent, for assuming that the process of development might be pushed forward a stage, and the embryo of a bird come forth a beast ; but no such instances have been known. We should therefore be fully justified in rejecting the supposition without further enquiry, even if our objection to receiving it rested simply upon the ground that there was no evidence to support it. But there are positive reasons for rejecting it. It is a matter of familiar knowledge, that the young of all the ocean birds—the albatross the petrel and others of that class—are absolutely unable to provide their own food, and require, until the time of arriving at full plumage, the most unremitting attention on the part of their parents. In what manner is it supposed that the young albatross, emerging, according to this theory, from the egg of the turtle, is nourished during this period of helplessness ? Do the supporters of this doctrine suppose that the turtle, relinquishing its habits, collects and supplies the appropriate food for this monster, as it must appear in its eyes ; or, in other words, do they assume a miracle? for to this it comes after all. And in the same way we may ask in what manner a seal, or a porpoise, produced from the ovum of a fish, is supported during its infancy. All animals of the class mammalia suckle their young ; and nature appears to have provided no substitute for the aliment thus supplied by the mother. Unless, therefore, we assume some unaccountable departure from known laws, some violation of the plainest analogies, the higher types which are assumed to be produced from these lower sources must perish in the first hours of their existence, instead of becoming the parents of innumerable races, to whom they in their turn are to impart an organization different from their own. It is only by these familiar illustrations that we can succeed in making palpable the unutterable absurdity which is veiled under the high-sounding phrases and specious generalities of this system. The idea of an ape, for instance, producing and nourishing a human being involves, perhaps, rather a moral than a physical contradiction, or at least its physical impossibility, may not be susceptible of demonstration— but the idea of a frog suckling an ape! And yet this theory is invented to get rid of everything which savours of a miracle, and to bring the formation of all species under the operation of law!
But further, the very idea which we form of a law of nature is opposed to this idea. A law is something uniform, universal, irresistible. If it were said that, at a certain period of their existence, every race passes into another form—as the tadpole into the frog, or the caterpillar into the butterfly—the idea of a law would be maintained. But this is not urged. It is only particular individuals who are supposed thus to advance, while the mass remain in their pristine condition ; and not merely in the assumed law introduced with this limitation, which in fact makes it a miracle instead of a law, but it is further assumed that the law itself has ceased to operate. This is necessary, because it would be absurd to suppose that in all the ages during which man has been associated with animals, as a shepherd, or a hunter, or an observer of nature, no instance of such a transformation in any one species should have occurred or been observed. What, then, is this law which is exceptional and temporary, which affects few individuals in number, and which is limited in its duration? We know that the other natural laws, so far as we can trace them, have no other limit in a race than the extent of the universe, nor in duration than that of time itself. The light that comes to us from the furthest and dimmest of the orbs which lie beyond the range of our unassisted vision, is of the same character and composition as that which emanates from the sun ; and the researches of the geologist have afforded an unsuspected proof that, in the earliest periods of our world—in what we may term the infancy of its existence—the light which then shone was identical with that which now reveals to us the face of nature—for the eyes of some of the inhabitants of our globe in that remote period have been preserved, and they show, by the sameness of their structure with those of animals at the present time, that the light to which they were adapted was the same as now. And so with the law of gravitation. We know that the mysterious influence which we have thus named, but which, we may observe in passing is as much beyond our conception now as before it had a name, which maintains the equilibrium of our system, and preserves the planets in their orbits, extends also in the remotest boundaries of space, and unites our system in permanent relation with every star which shines. And this also has existed from the beginning, and must endure to the end, since its cessation would involve the universe in one common ruin. So also with the laws which regulate the growth, decay, and reproduction of all organized beings. These are identical now with what they were when the first shell-fish adhered to the early rocks which formed the shores of the primitive ocean, and are uniform and universal in their operation. These animals derived their nutriment from the surrounding waters, they lived out their allotted period, they reproduced their race, and then perished, leaving their bodies to decompose in obedience to chemical laws, and their shelly coverings to enlighten or bewilder future philosophers. In fact, the very idea of a law is, as we have stated, something uniform, universal, and permanent, and the idea of a miracle is something exceptional to, and which cannot be explained by ascertained laws. Taking this theory therefore in itself, we are warranted in the conclusion that it is a mere unsupported hypothesis, and not merely without any basis from observed phenomena, but even contradicted by these.
  Let us pass, then, to two of the direct arguments by which the theory is defended. They are—1st, The progression of the forms of life, as the world became older, coupled with the uniformity of organization observable at the present time; and, 2nd, The assumed inconsistency of the received opinions, with fitting conceptions of the character of the Deity. I will advert briefly to each.
   I have already said that I do not propose now to discuss facts, but to examine arguments ; and I do not, therefore, stop to point out the many seeming, and some real exceptions to the assumed law of progression. The general fact may be admitted, that the earliest forms were of the lowest and simplest kind, and that every succeeding epoch was distinguished by an advance in organization. In the first formation we have shell-fish and invertebrate animals—then fish, then reptiles, then birds, and then the mammalia—the latest forms of these   approaching most nearly to the present type, and, in some instances, being scarcely distinguishable from them ; so that the present is connected with the past as part of the same scheme. And, throughout the whole series, we find that this progression is accompanied by a partial continuance of the same species, forbidding, it is said, the idea which some have entertained of an entire destruction and new creation at every successive epoch. And, as I have already pointed out, there is an uniformity of organization among all the species of the different classes and families, which we cannot refer to any actual purpose to be accomplished in the functions of the organ. These, then, are the phenomena to be explained. And the question is, to what hypothesis do they lead ? It is not now the old question, which the standard works on Natural Theology were intended to solve whether design argued the existence of a designer, or whether all was not the result of some fortuitous combination of atoms. It is conceded that there is an Author and Contriver of the system, to whose foresight and power every manifestation of being is, remotely, indeed, but absolutely, traceable. Nor is the question, as some have put it, whether we are to imply a creation according to law, or one arbitrary and capricious ; because every one who reasons on the subject admits the existence of laws to which every being is subject, and in conformity with which every being is framed. The question really is, whether all natural phenomena, from the lowest to the highest, are to be taken as involved potentially in the original constitution of matter, so that the successive appearance of new orders of being with superior organization and higher functions, including not merely life and volition, but reason, fancy, imagination, and religion, is as strictly a matter of course as the birth, assimilation and secretion, growth, decay, and death of an animal ; and Newton and Shakspeare existed potentially—I was about to say in the first oyster, but that would be understating the case, I ought to say in the ultimate particles of the diffused nebulous vapour which is assumed to have been the first condition of the universe ; and whether they do not derive their descent in a direct line from the earliest and simplest forms of animate existence? It is this assumption which we have to examine. We are not bound, if we reject this hypothesis, to suggest any other mode of accounting for the appearance of these beings, because it is admitted on all sides that the beginnings of all existence is a matter beyond our comprehension, unless we assume the being of a Creator as the only and the sufficient cause. If we accept this hypothesis, we must refer the original form, tendencies, and powers of matter involving all these marvellous results to the fiat of the Deity, without pretending to understand the motive or the mode of his operations ; and if we reject it, we do the same.
 The main support of this theory is what is termed the nebular theory, to which I have already referred. I may just remark in passing, that this theory appears to be shaken by recent discoveries, since some of the assumed nebulæ have been shown to consist of separate stars instead of a diffused nebulous matter; and that, therefore, it affords at present but as an unubstantial basis upon which to erect any elaborate hypothesis. But, admitting it to be true, it affords no support ; even by analogy, to this so-called theory of development.
 We may assume, if we please, that our planet, and the system of which it forms a part, and the universe with which that system is connected, originally existed as a diffused vaporous mass, in which all the elements were blended in chaotic confusion, and out of which the present starry universe has been evolved in obedience to the natural laws of gravitation, heat, electricity, and chemistry. This may be admitted as an hypothesis, because it is, in some respects, analogous to processes which are familiar to our daily experience, and may be shown to be a possible result of known laws. To take a familiar illustration of one part only of the process—vapour condenses into drops, and then drops assume a globular form, in obedience to the laws of gravitation. Here we are able to understand the mode of operation, and we see that there is nothing in it inconsistent with the results of observation, or beyond the possible power of existing forces to accomplish. But that inorganic matter should pass into organic forms, having life, sensation, and the power of reproduction, is not merely unwarranted as an inference from the assumed condensation of matter, but is not to be explained by any known result of the powers to which mere matter is subject, or, if our opponents so please, with which it is endowed. We may admit that the world is only condensed vapour, because we know that all substances may be volatalized by heat, and that, when the heat is withdrawn, they resume that which, to us, is their ordinary form ; and thus the phenomenon would be simply the arrangement of the particles of matter in new forms and in various combinations, in obedience to powers which we see in continued operation. But the passage from inorganic to organized matter involves the introduction of new powers, which there is absolutely no ground whatever for assuming, except the fact that organic forms do actually exist. To assume such a passage is, therefore, to reason in a circle. The existence of these occult powers is assumed to explain the fact, that living beings are found in the world, and then the existence of these living beings is appealed to as a proof that such powers must exist.
 I conclude, therefore, that this first ground for introducing the theory of creation by law, in reality lends no support to the hypothesis. The appearance of the earliest and simplest vegetable and animal upon the earth was a phenomenon distinct in kind, and not merely differing in degree from all that had preceded it, and cannot be referred to any result of the powers which had been working to arrange and solidify the globe. It implies the introduction of new powers and higher laws—and the same remark may be made to the supposition that these early forms of life have gradually developed themselves into all the infinitely various species which at present exist. I ask, what is there in the fact that mollusks appeared upon the earth at an earlier period than fishes—fishes at an earlier period than reptiles, reptiles than birds, and birds than mammalia—which should lead us to suppose that all these higher forms are derived from the more simple natural descent? It is another form of the old fallacy which we express proverbially, by the saying that, "Tenterden church steeple was the cause of Goodwin Sands ;" that is, the assumption that, because one phenomenon is antecedent in point of time to another, therefore it is the cause of it. And I may venture to say, that, of all the hypotheses which have been invented to account for the phenomena of life and organization in its progressive appearances and present form, this is the most complicated and unsatisfactory. I could rather believe that the various forms of being were produced at once from the earth—that, for instance, as silex and nitric acid are said to be the materials from which certain insects are produced, other substances were fitted to produce elephants, others whales, others horses, and so on throughout the whole range of animated nature, and that these, once produced, continued to propagate their species according to the laws of their organization—than that frogs should be developed into men, or oysters into oxen. In the one case there is only one difficulty to be got over, how rude and inert matter should assume organization and vitality ; but in the other, there is not merely this original difficulty, but a similar difficulty to be overcome at every transformation. And I venture to predict, that, if the theory we are examining should hold its ground, it will ultimately assume this shape, and the poetical description of Milton will be held to be a strictly scientific exposition of facts when he talks of

 The cattle in the fields and meadows green
 Pasturing at once, and in broad herds upsprung :
 The grassy clods now calved. Now half appeared
 The tawny lion pawing to get free
 His hinder parts ; then springs as broke from bonds.
 And, rampant, shakes his bearded mane, &c.

 and all the rest of that fanciful description.
 With regard to the uniformity prevailing throughout different families and species of the same class, and that also which prevails throughout all living beings, however widely differing in appearance, I remark that this uniformity may be referred to other causes than that of relationship by descent, while the differences we observe appear to be incompatible with such relationship. But, upon calm reflection, there appears nothing to this uniformity which we should not have a right to anticipate. All living beings derive their support mediately or immediately from inorganic matter—plants almost without exception, immediately ; and animals in every instance through the medium of plants ; or, in the case of those who live by prey from animals who have been nourished by plants. Now, it is found that the ultimate elements which contribute to the support of organized beings is very limited. They consist almost exclusively of the gases, oxygen, hydrogen, and nitrogen, and of carbon. There are some other subtances—as lime, which forms a part of the bones of animals, and enters also into the composition of plants ; silex, which forms part of the cuticle of some of the families of the grasses, as wheat, the bamboo, and some others. It must be obvious, then, upon a moment's reflection, that this simplicity of the inorganic constituents of bodies, imposes a certain degree of uniformity in vital structure and functions. As the elements of living forms must be limited by and identified with those of the inorganic matter from which they are derived, there is necessarily a boundary which organized matter is forbidden to overstep ; it can have nothing which is not found within the limits of the mineral kingdom.
Taking this, then, as the starting point in an investigation, it is obvious that a great similarity and even identity of organization in certain essential particulars, must be expected throughout all organized beings. As all have to derive their nutriment from the same ultimate elements, which they receive into the system and assimilate to their own substance, we might anticipate, independently of experience and observation, that there would be a marked similarity, or rather analogy, both in the organs by which this process was performed, and in the results which it produced. We might be surprised at the prodigal scarcity of form, colour, function, and attribute, which we discover in the course of our investigations, for there is nothing which could give us a right to expect this ; but we ought to be prepared to find in all this seeming difference a fundamental unity of organization and substance. It would therefore be a matter of surprise if we were to find anything in the organs with which any two families of plants are endowed for the absorption and assimilation of these simple elementary substances, essentially different from each other—while, on the other hand, the natural expectation would be, that organs designed to perform similar functions in reference to the same substances, would present throughout one unbroken analogy, and would shew in all a similarity, and in many an identity of structure. In the same manner with animals, which derive their support from organic matter, we must look for the same analogy of structure—the same general arrangement of organs, and an identity, so far as the functions to be performed are the same.
When, however, we thus find in the constitution of nature an adequate explanation of this uniformity, it is a gratuitous and unphilosophical assumption to attribute its existence to a supposed law of progress and parentage, which is both unnecessary and unproved. The organs of every animal and plant have a direct and immediate reference to the circumstances in which they are placed and the functions which they have to discharge. There is nothing wanting and nothing superfluous—unless, indeed, it is said it is superfluous to give to the hog as many bones in its neck as to the cameleopard, or as many bones in its feet as man ; or to give the whale in its forefin the same number of bones as in the human hand and arm. This argument has been used, but it is in reality only an appeal to our ignorance. We do not know why one type should thus run through all families of the same class, and perhaps we are not likely to know. But at least we may say that these facts lend no support to the theory we are examining. If it were argued that hogs and whales were degenerate men, these resemblences might be called in aid of the hypothesis, and it might be said that they still retained, in this particular, some traces of their origin which could be referred to no other source. But the theory presupposes the reverse order—an order of progress and not of degeneracy ; and there is nothing in the assumed parentage of these animals to which this so-called anomaly can be referred.
 There one other topic to which I can advert, and I have scarcely left myself space to touch upon it : the assertion that the ordinary idea of creation by the direct intervention of the Deity, is inconsistent with the ideas which we ought to form of His attributes ; since it is degrading to Him to suppose that He should have interfered at every epoch to call into existence all the minute and evanescent forms which people the earth—and which have successively appeared, have lived out their allotted term, and have disappeared as living beings from the face of the globe. I regret that I can do no more on this branch of the subject than indicate the grounds upon which I am compelled to dissent from this argument, since it is perhaps the most interesting and important branch of the subject. I may, however, briefly observe, that in the first place the difference between the supporters and the opponents of this theory, is merely one of time. They admit, or rather their argument implies, that all these forms were foreseen and provided for ; that the time, place, and circumstances of their appearance were prearranged—that all was fitted for their production, their nourishment, and their continuance—that nothing was left to chance, but everything placed under strict subordination to law. And therefore all this assumed derogation from the majesty and greatness of the Deity, is equally chargeable upon their scheme, excepting that they suppose they escape it by placing the provision for their appearance in the first beginnings of creation instead of supposing it to be contemporaneous with this formation. And in the second place, that the whole argument proceeds from the habit which all of us are too apt to acquire, of supposing that God is altogether such a one as we are, and of assuming that what to us appears important or trifling is so in its essence and in reality. It is, in fact, measuring the infinite by the scale of the finite. To me the whole argument appears singularly unphilosophical. With regard to man, distinguished as he is by faculties which have reference to the future as well as to the present —requiring another state of being for the completion and development of his intellectual, moral, and religious nature—in one sense the lord of material and animated nature, I assume that he is greater in himself, and more important in the eyes of his Maker, than any other class of beings—but with this exception I see no difference in dignity or destiny among all living creatures. Excepting in bulk, what distinguishes the elephant from the ant? The one is as perfectly organized as the other in reference to purposes it has to fulfil—its instincts are as marvellous—its functions as important. There is the same care manifested in adapting it for the circumstances in which it is placed and in providing for the support of the individual and the perpetuation of the species ; and who shall say that the creation of one or the other is derogatory to the Infinite Majesty ?

 South Australian Register 16 May 1849,

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