"Credat Judæus Apella;Non ego."
"Credat Judæus Apella;Non ego."
We pass to the next chapter in the history, which professes to explain the gradual formation of a solar system by a process of cooling and shrinking, to which the central orb is exposed. And here we are met by a difficulty at the outset; for the existence of comets with their very eccentric orbits is wholly irreconcilable with the theory. At their perihelion, many of these bodies pass within the orbit of Mercury, while the aphelion of some lies without the path of Uranus. Where were they, when the body of the sun filled up the whole of the vast sphere circumscribed by the orbit of the remotest planet? If we suppose that they are late comers, after the rest of our system was perfected,—that they were generated by themselves in distant regions of space, and, having strayed about, orphan-like, for a while, they accidentally crossed our track, and were taken as adopted children into our family, another question remains to be answered. Why did they not remain in their first position, absorb their full share of nebulous matter, beget a respectable family of planets, and take rank as chiefs of their own clan? These comparatively anomalous bodies are great stumbling-blocks for thesoi-disanthistorians of creation.
Again, if an immense orb be formed, the parts of which cohere strongly enough for the whole to turn upon its axis as one body, the process of cooling can go on only from the surface. A crust may finally be formed there; but we see not how the refrigeration and shrinking of the interior parts can then go on separately, until the mass in the centre finally becomes detached from its envelope, like a shrivelled nut from its shell. Our earth is cooling down at this moment, unless the warmth which it receives from the sun exactly counterbalances the loss by radiation of internal heat. But the exterior and interior do not cool by different radiations, nor is there, so far as we know, the least tendency in the central mass to shrink separately, so as to detach itself from the surrounding crust. As deep as we can penetrate towards the centre, we find the heat regularly increase,—just as we might expect, if the only absolute loss of heat be from the surface.
If the matter now concentrated in the sun, and that which forms the several planets with their secondaries, were all moulded into one mass, and then dilated so as to fill the vast sphere of which the orbit of Uranus forms a circumference, the substance would evidently be in a state of extreme tenuity and diffusion. Immense as the mass of the sun now is, it is but a mere nut at the centre of the grand globe which we are now considering. Expanded to such vast dimensions, we cannot conceive of it as a solid spheroid turning upon its axis, but only as a mass of fluid or vapor, in which a circular motion would generate only vortices or whirlwinds. In such an aggregation of subtile matter, no crust could be solidified on the outer ring, and then detached from the mass within; indeed, any separation of the parts under such circumstances is inconceivable. Even a rotary motion could not be established in it, except by an impulse received from without; for there is every reason to believe, that the movement of a homogeneous fluid towards its centre, if it could take place without disturbing causes, would be in radial lines, and not in a spiral.
Our author brings into view all the mathematical proportions and uniform relations which exist between the constituent bodies of the solar system, in order to indicate the probability of their formation from the constant working of one material cause. Thus he remarks, that the primaryplanets all move nearly in one plane, and "show a progressive increase of bulk and diminution of density, from the one nearest to the sun to that which is most distant." But he passes over other characteristics of these bodies, equally important, which are quite irregular, and cannot be traced to the operation of one law. Compare the periods of rotation on their respective axes, and we find no correspondence, no indication that the revolving motion was imparted to all by one inflexible law. The first four planets, counting from the sun, perform their rotation in nearly the same time, namely, twenty-four hours. But Jupiter's period is a little less, and Saturn's a little more, than ten hours. Again, Jupiter's axis of rotation is nearly perpendicular to the plane of the ecliptic, while that of Mars is inclined at an angle of fifty-nine degrees forty-two minutes. Another irregularity, still more fatal to the theory, is found in the number of satellites by which the respective planets are attended. Saturn has seven, beside the two rings; Jupiter has four, Mars has none, and the earth has but one. On the single hypothesis, that our system was formed by rings successively thrown off from a central body by a process of refrigeration and contraction, these irregularities are inexplicable. Mars, it seems, did not shrink at all, while Jupiter cast off four separate rings, and the earth produced its single moon. The distances of these bodies from their primaries are also quite irregular; in the case of Jupiter, the outermost of the satellites revolves at a distance which is only twenty-seven times the radius of the primary, and the innermost is distant but six times that radius. This planet, consequently, has shrunk to one twenty-seventh part of its original diameter, and in so doing, has formed four moons; the earth has shrunk to one sixtieth part of its first diameter, and still has produced but one satellite. If the same law had prevailed in the two cases, we ought to have nine or ten moons.
We need not analyze with any great minuteness the geological facts and hypotheses incorporated into this magnificent history of creation. As will be seen hereafter, the violent and sweeping transformations and convulsions that the earth's crust has undergone directly conflict with our author's theory, and afford the strongest presumption, that an extraneous cause has frequently interfered, at different periods, to repair the desolation produced by the unassisted working ofnatural laws, to bring order out of chaos, and to people the desert earth anew with animated tribes. The only general fact of much moment, which our author has drawn from the discoveries of geologists, for the confirmation of his own hypothesis, is, according to his own account, one of the most questionable doctrines in the whole science,—one of a negative character, on which we can never rely with full assurance, till the researches of man have probed every fold, and examined every thread in the texture, of the earth's garment, and thus shown that no evidence can possibly be discovered to the contrary. The alleged fact is that, in the early formations of rock—the first pages in the history of the earth's surface—are found the remains of animals and vegetables only of the lowest type and most imperfect development; while, in the later strata, forms more and more advanced are discovered; so that there seems to have been a constant progress along the line leading to the higher forms of organization. The testimony which goes to support this assertion is wholly negative. The geologist reasons thus: The more perfect organisms have not been discovered in the earlier strata;therefore, they do not exist in them. When, in a different connection, it suits our author's purpose to throw doubt on the very postulate which is here admitted, he holds the following language.
"These, it must be owned, are less strong traces of the birds than we possess of the reptiles and other tribes; but it must be remembered, that the evidence of fossils, as to the absence of any class of animals from a certain period of the earth's history, can never be considered as more than negative. Animals, of which we find no remains in a particular formation, may, nevertheless, have lived at the time, and it may have only been from unfavorable circumstances that their remains have not been preserved for our inspection. The single circumstance of their being little liable to be carried down into seas might be the cause of their non-appearance in our quarries."—p. 95.
"These, it must be owned, are less strong traces of the birds than we possess of the reptiles and other tribes; but it must be remembered, that the evidence of fossils, as to the absence of any class of animals from a certain period of the earth's history, can never be considered as more than negative. Animals, of which we find no remains in a particular formation, may, nevertheless, have lived at the time, and it may have only been from unfavorable circumstances that their remains have not been preserved for our inspection. The single circumstance of their being little liable to be carried down into seas might be the cause of their non-appearance in our quarries."—p. 95.
In truth, the researches of geologists are every day bringing to light new facts, which compel them to modify or abandon many of the positions they formerly held; so that a considerable portion of the science is a mere quicksand of shifting theories. We need only allude to the various suppositions respecting the origin of drift, and to the numerous modifications of the glacial theory. Important discoveries have beenmade within a short time, showing that certain animal tribes had their origin much farther back than was at first supposed. A few years ago, reptiles were believed to be the highest type of life that existed during the era of the new red sand-stone. But Professor Hitchcock's recent discovery in this stone of the footprints of gigantic birds has added a higher class to the zoölogy of the period; and within a few months, in the same red sand-stone of the Connecticut valley, tracks of two or three species of quadrupeds have been found, some of them being probably mammifers of a lower grade. It is true, no fossil remains of these animals have been brought to light; but this want only renders the discovery more significant for our present purpose. It shows that certain animals must have lived at the period in question, though their remains have not yet been found; and from the greater age of the rocks then formed, and the consequent greater number of convulsions of the earth's surface to which they have been subjected, these remains may have entirely disappeared. It is a curious fact, also, that the animal remains of that period, which have come down to us, belong to genera so constituted, that their bodies might well survive, if we may so speak, the shocks which would have destroyed every trace of some more delicate, or more finely organized, beings. We find remains of the flint-shielded animalcules, the hard-shelled mollusca, and the cartilaginous fishes; but the bodies of mammalia, birds, and even the higher species of fishes, some of which we may suppose to have been more tender and corruptible, have utterly perished. Here and there, an individual of their number left the print of its foot on the sand, which subsequently hardened into rock, and brought down to our times a faint vestige of its past existence.
We are not attempting to impugn the credit of geological science in general, which would be a wholly futile task. The multitude of facts respecting the present constitution of the earth's crust, recently made known by laborers in this department, are among the most curious and most pregnant discoveries of modern times. But when we come to the formation of theories respecting the past history of the earth, in order to account for the phenomena at present visible on its surface, we are evidently afloat on a sea of conjecture, each hypothesis being valid only till a more plausible one is proposed,—which happens very frequently,—or till it is effectuallydisproved by some new discovery in the rocky strata. A fertile imagination and a bold face are among the most striking traits of our more daring geologists. Grant to one of this character a few modest postulates,—give him certain millions of years, a sufficient number of earthquakes, a whole battery of volcanoes, a few ocean deluges, and the rise and fall of half a dozen continents,—and he will frame a theory off-hand, which will account for the most perplexing phenomena. Our author is certainly entitled to take his place at the very head of this class of speculatists.
In accounting for the work of creation by the natural and unassisted development of the inherent qualities of brute matter, the great difficulty is found at the first link in the chain of animated being. How can we explain the commencement oflife? We must have a clear idea of the whole scope of this problem, before we can make any attempt at its solution. Life, then, isnotmere organization, though most materialists, philosophers, like our author, willingly confound the two things; to hear them reason, one would almost suppose that there was no difference between a dead man and a living one. Organization is subservient to life, ministers to it, manifests it,—supports it, if you please,—but does not constitute it. He must be a bolder man than we are, who will undertake to saywhat it is; but we can very safely declarewhat it is not; and in any particular form or aggregation of matter, whether organic or inorganic, we can give a shrewd guess as to its presence or absence. It may be said, that we beg the question by assuming that organization is not life; it may be so; but it is quite too much to allow the materialist quietly to take the opposite doctrine for granted. He must know the full extent of his task,—that it is necessary for him not only to construct the machine, but actually to set it in motion, so that it shall afterwards run on of its own accord. It is very easy to frame a partial definition of life, by merely describing one or two of its characteristic functions; and then, because some action can be detected between the particles of brute matter, which resembles the exercise of these functions, boldly to declare that the whole mystery is solved. Thus it is said, that life is nothing but the accretion of similar substances, or the addition of like unto like; and as this occurs in crystallization, which is confessedly a phenomenon of inorganic matter, therefore there is no fundamental differencebetween the properties of living and dead substances. We deny the first proposition; nutrition is not the only characteristic of life, and the nutritive process, whether in vegetables or animals, is not mere accretion, but assimilation. It has been said, though the assertion is by no means fully proved, that assimilation is only a finer kind of chemistry, the constituent principles being brought together only by their natural affinities. Even if this were true, if the stomach and the digestive apparatus were only a well furnished chemical laboratory, fit for conducting the most delicate experiments, the great difficulty would still remain. The question might yet be asked, Where is the chemist? And this is the fundamental question, which the materialists never attempt to answer, but quietly evade.
The difference between an inorganic and an organic body has been explained by Coleridge clearly enough for our purpose. In the former,—a sheaf of corn, for instance,—the whole is nothing more than a collection of the individual parts; in the latter,—an animal,—the whole is the effect of, or results from, the parts. In the latter case, the whole is every thing, and the parts are comparatively nothing. One of the great effects of life is to keep the parts in subjection to the whole, making them contribute to its support and growth, and thus maintaining the unity of the system. The stomach digests, the lungs inhale air, the heart beats, and the blood circulates; and as the joint effect, or as the common supporter,—it matters not which,—of these operations,lifecontinues, and the animated being is a unit; it has not merely virtual, but essential unity. The reciprocal action of the respiratory, circulating, and nervous systems is absolutely necessary to life. The animal dies, and this unity, this subservience of the parts to the whole, immediately ceases. In the functions of the living body, it may be that the ordinary laws of chemistry are preserved, and that the elements of carbon, oxygen, and hydrogen combine and separate according to their ordinary affinities, and in no unusual proportions. But after death, at any rate, quite a different set of chemical laws come into play, and produce a result which is the very opposite of that before effected. There is no longer any unanimity or coöperation; instead of sustaining or building up the animal tissues, the affinities now in operation tear down, destroy, and resolve them into their ultimate elements,—eachpart following out its own law of destruction or resolution, irrespectively of the others.
"There is in living organic matter a principle constantly in action, the operations of which are in accordance with a rational plan, so that the individual parts which it creates in the body are adapted to the design of the whole; and this it is which distinguishes organism. Kant says, 'The cause of the particular mode of existence of each part of a living body resides in the whole, while in dead masses each part contains this cause within itself.' This explains why a mere part separated from an organized whole generally does not continue to live; why, in fact, an organized body appears to be one and indivisible. And since the different parts of an organized body are heterogeneous members of one whole, and essential to its perfect state, the trunk cannot live after the loss of one of these parts."—Müller's Physiology, Vol. I., p. 19.
"There is in living organic matter a principle constantly in action, the operations of which are in accordance with a rational plan, so that the individual parts which it creates in the body are adapted to the design of the whole; and this it is which distinguishes organism. Kant says, 'The cause of the particular mode of existence of each part of a living body resides in the whole, while in dead masses each part contains this cause within itself.' This explains why a mere part separated from an organized whole generally does not continue to live; why, in fact, an organized body appears to be one and indivisible. And since the different parts of an organized body are heterogeneous members of one whole, and essential to its perfect state, the trunk cannot live after the loss of one of these parts."—Müller's Physiology, Vol. I., p. 19.
The apparent exceptions to this statement—as in the case of the polypes, which multiply by fissiparous generation, or by spontaneous division of their bodies into parts, each part becoming a perfect animal—are only apparent. These creatures, which are low down in the scale of being, exemplify what Mr. Owen calls "the law of vegetative or irrelative repetition," as they have many organs performing the same function, and not related to each other by combination for the performance of a higher function. Thus, a Polygastrian has many assimilative sacs, each performing the office of a stomach irrespective of the rest. In the insect tribe, the respiratory function, instead of being performed by one set of lungs for the whole body, is carried on through a series of minute and highly ramified tubes, which traverse every part of the body, and open to the air by a great number of orifices. In some instances, both respiration and digestion seem to take place over the whole surface of the body; for Trembley found at least one case, in which the animal digested its food equally well, after it had been turned inside out. A number of similar parts being repeated in each segment of the individual, the body can be divided, and the several portions, each still containing some of all the organs essential to the whole, will continue to live separately. The severed parts will even continue to grow, and to develope other organs convenient for individual existence. But most animals, especially the more perfect, do not constitute an aggregateof similar parts united by one trunk, and therefore propagation by division is in them impossible. The ovum, when separated from the parent, is an entire animal onlypotentially; during its development, the essential parts which constitute theactualwhole are produced. In the case of the polyps, we have only to suppose that the ovum remains connected with the parent being, till all, or nearly all, its essential parts are produced. It is then shed not as a mere ovum, but as an animal nearly or wholly complete.
Now, all the instances adduced by our author, to show similarity of action in the organic and the inorganic world, are irrelevant. The analogies are not merely imperfect; they are no analogies at all. Crystals increase by the aggregation of new particles on the external surfaces of the parts already formed; there is no consentaneous operation of the parts on the whole. The molecules of crystals are homogeneous throughout, and the several aggregates of these molecules are independent of each other; while organized bodies are composed of parts perfectly dissimilar from each other, but all of which conspire to one end. "The growth of organized bodies," says Müller, "takes place in all particles of their substance at the same time, while the increase of the mass in inorganic bodies is produced by external apposition." Frostwork on the windows may resemble vegetableforms; but it has no resemblance whatever to vegetablelife. Electricity may counterfeit theaction of life, for a moment, on a particular limb, by causing the muscles to twitch; but it does not counterfeitlife itself, by causing all the parts again to contribute to the sustentation of the whole. A French chemist, by electric action, may have producedglobulesin albumen; there is nothing very wonderful in that; any one may blow bubbles in a viscid fluid. The resemblance between these globules and proper germinal vesicles amounts to nothing more than similarity of outward shape; there is no more real resemblance between them than between the oval lump of chalk which farmers sometimes put into a hen's nest, in order to deceive poor Dame Partlet, and the real egg which the hen deposits by the side of it. Certainly, the imponderable agents, heat, light, and electricity, are in some mysterious wayconnected withlife, so as to contribute to its support; there is nothing more in this assertion than in the familiar proposition, that a seed will germinate only under theproper conditions of soil and climate; but that these agents, acting on inorganic matter, evercreateorcommencelife is a pure hypothesis, not supported even by the shadow of a fact.
Having thus shown how weak are the general considerations in favor of the theory, that animated beings may be created out of inorganic matter by mere natural laws, we should proceed to consider the direct evidence adduced to prove that life has actually been produced in this way. Here the whole question is opened respecting the alleged instances of equivocal generation, and we have neither space nor ability to discuss them at length. Those who are curious respecting the question may find a brief summary of the evidence on both sides in a former number of this Journal.[1]We can mention only a few facts and arguments, which show the extreme improbability of the doctrine supported by our author and a few other theorists.
In the first place, it is remarkable, that all the races of animated beings, which are entirely within the range of our powers of observation,—which have such a size and locality that we can study and accurately determine their organization and habits,—are unquestionably produced from parents of their own kind. Only the minute microscopic animals are now supposed to be generated spontaneously; and this alleged fact rests not on direct proof, but only on our inability in certain cases to trace the process of their production in the ordinary way. As many of these animals, in their perfect state, are not more than the twelve thousandth part of an inch in diameter, it is not much to be wondered at, that we should not be able in all cases to discover their ova, or to follow these ova through all their stages of development into the complete being. It is farther remarkable, that these animalcules, when once produced, whether by spontaneous or natural generation, are all found to be provided with the organs or requisite means for continuing their species, and, in fact, for multiplying their number from themselves with astonishing rapidity. As they certainly have children, it seems reasonable to suppose, according to the analogy of all the higher animated tribes, that they also had parents. The ancients supposed, that the worms and insects which appearin decaying organic matter were generated there by the decomposition of the substance, without the previous agency of individuals of the same stock. Every schoolboy is acquainted with Virgil's mode of obtaining a new swarm of bees from the decaying carcass of a heifer. Subsequent researches, made with more care, and perhaps with better instruments of observation, have entirely disproved the hypothesis, and show that the maggots were produced in every case from eggs deposited by flies or other insects, and were afterwards themselves developed into the state of perfect insects. Then it seems reasonable to believe, that the improved observations of future times will clear up the only remaining difficulty, and show how the infusory animalcules also are generated from beings of their own kind.
These minute creatures are prolific to a degree that transcends all calculation; and they exist, either in the egg or maturely developed, in inconceivable numbers. A single wheel-animalcule,Hydatina senta, which was watched for more than eighteen days, and which lives still longer, is capable of a fourfold increase in twenty-four or thirty hours; a rate of propagation which would afford in ten days a million of beings. From their tenacity of life, extraordinary powers of reproduction, and incalculable numbers, their united influence may be said to be far more important, in all the great operations of nature, than that of the larger and more perfectly developed organisms. They swarm in all the seas, and play an important part in choking up harbours and forming great deposits at the mouths of rivers. The remains of those which have perished form great beds and strata in the crust of the earth. The silicious stone, called Tripoli, is entirely composed of such remains; at Bilin, in Bohemia, there is one stratum of this substance, fourteen feet thick, one cubic inch of which is estimated to contain forty-one thousand millions of individuals. Their extreme tenacity of life is evinced by the fact, that many of them may be entirely desiccated, and preserved in pure sand for several years, after which, on the application of a drop of water, they may be restored to life. In this dried state, M. Doyère exposed some of them to a heat equal to that of boiling water, and afterwards revived them; though, in an active state, if subjected to a much lower temperature, they perish. If, then, the fully developed and mature can resist such powerful extraneouscauses of destruction, how much more must the ova possess the power of enduring them without losing their latent life! The following extract from Professor Owen's Lectures shows the bearing of these facts upon the question of equivocal generation.
"The act of oviparous generation, that sending forth of countless ova through the fatal laceration or dissolution of the parent's body, is most commonly observed in the well-fedPolygastria, which crowd together as their little ocean evaporates; and thus each leaves, by the last act of its life, the means of perpetuating and diffusing its species by thousands of fertile germs. When the once thickly tenanted pool is dried up, and its bottom converted into a layer of dust, these inconceivably minute and light ova will be raised with the dust by the first puff of wind, diffused through the atmosphere, and may there remain long suspended; forming, perhaps, their share of the particles which we see flickering in the sunbeam, ready to fall into any collection of water, beaten down by every summer shower into the streams or pools which receive or may be formed by such showers, and, by virtue of their tenacity of life, ready to develope themselves wherever they may find the requisite conditions for their existence."The possibility, or, rather, the high probability, that such is the design of the oviparous generation of theInfusoria, and such the common mode of the diffusion of their ova, renders the hypothesis of equivocal generation, which has been so frequently invoked to explain their origin in new-formed natural or artificial infusions, quite gratuitous. If organs of generation might, at first sight, seem superfluous in creatures propagating their kind by gemmation and spontaneous fission, equivocal generation is surely still less required to explain the origin of beings so richly provided with the ordinary and recognized modes of propagation."—pp. 31, 32.
"The act of oviparous generation, that sending forth of countless ova through the fatal laceration or dissolution of the parent's body, is most commonly observed in the well-fedPolygastria, which crowd together as their little ocean evaporates; and thus each leaves, by the last act of its life, the means of perpetuating and diffusing its species by thousands of fertile germs. When the once thickly tenanted pool is dried up, and its bottom converted into a layer of dust, these inconceivably minute and light ova will be raised with the dust by the first puff of wind, diffused through the atmosphere, and may there remain long suspended; forming, perhaps, their share of the particles which we see flickering in the sunbeam, ready to fall into any collection of water, beaten down by every summer shower into the streams or pools which receive or may be formed by such showers, and, by virtue of their tenacity of life, ready to develope themselves wherever they may find the requisite conditions for their existence.
"The possibility, or, rather, the high probability, that such is the design of the oviparous generation of theInfusoria, and such the common mode of the diffusion of their ova, renders the hypothesis of equivocal generation, which has been so frequently invoked to explain their origin in new-formed natural or artificial infusions, quite gratuitous. If organs of generation might, at first sight, seem superfluous in creatures propagating their kind by gemmation and spontaneous fission, equivocal generation is surely still less required to explain the origin of beings so richly provided with the ordinary and recognized modes of propagation."—pp. 31, 32.
Recent accounts show, that the dust collected from the atmosphere at sea, many miles from land, generally contains some of these dried animalcules and their ova. Many of these germs can be developed only in particular localities, or under certain conditions which are rarely fulfilled. Consequently, if there were but few of them, the species might perish, because those few might not find their appropriate home. But such an accident is guarded against by the vast multiplication of these germs and their wide dispersion; for, unlike all the higher tribes of beings except man, the same species is often found in all regions of the globe. Very few, in comparison with the whole number, may find a propernidus; but thesefew then propagate with such marvellous rapidity, as fully to replenish, if not to increase, the original stock. Thus they have been enabled, as species, to survive even those destroying causes which exterminated all the higher forms of animals. Several species still exist, which were in being at the time of the cretaceous formation, though all the other animated races belonging to that period have perished. "These animalcules," says Ehrenberg, "constitute a chain, which, though in the individual it be microscopic, yet in the mass is a mighty one, connecting the organic life of distant ages of the earth."
In view of facts like these, we may surely say, that the existence of the infusory animalcules, and even of the entozoa, is conceivable, supposing they could only have been produced by parents of their own kind, and without having recourse to the anomalous and hypothetical doctrine of equivocal generation. We may not be able to trace their line of parentage, for our imperfect vision cannot follow the motes which play in the sunbeam, nor track them from their birth-place to their final home. But we know that they must be deposited in every layer of dust that falls from the atmosphere, that they must be inhaled with every breath which an animal draws, and be swallowed with every morsel and drop of its food. The experiments which seem to prove that living beings may be produced from pure inorganic matter are all explicable on the supposition, that adequate precautions were not taken to exclude every animal and germ capable of development from the substances experimented upon, and from the air which was admitted into the apparatus. On this ground, the experiments of Crosse and Weekes, cited by our author, have been quite generally rejected by scientific men, as hardly deserving of notice. We learn that the former was "discouraged by the reception of his experiments," and "soon discontinued them";—with good reason, for it does not appear from our author's account, that he adopted any precautions at all. Mr. Weekes seems to have been a little more cautious, and the consequence was, that he did not observe any appearance of life among the substances experimented upon for "eleven months," at the end of which time we may reasonably suppose, that his precautions ceased to have perfect effect. The only experiment, in which adequate means to guard against causes of error were taken, wasthat of Professor Schulze, of Berlin, which had a contrary result. We extract Mr. Owen's account of it.
"He filled a glass flask half full of distilled water, in which were various animal and vegetable substances: he then closed it with a good cork, through which were passed two glass tubes, bent at right angles, the whole being air-tight: it was next placed in a sand bath, and heated until the water boiled violently. While the watery vapor was escaping by the glass tubes, the Professor fastened at each end an apparatus which chemists employ for collecting carbonic acid: that at the one end was filled with concentrated sulphuric acid, and the other with a solution of potash. By means of the boiling heat, it is to be presumed that every thing living, and all germs in the flask or in the tubes were destroyed; whilst all access was cut off by the sulphuric acid on the one side, and by the potash on the other. The apparatus was then exposed to the influence of summer light and heat; at the same time, there was placed near it an open vessel, with the same substances that had been introduced into the flask, and also after having subjected them to a boiling temperature. In order to renew constantly the air within the flask, the experimenter sucked with his mouth several times a day the open end of the apparatus, filled with the solution of potash, by which process the air entered his mouth from the flask through the caustic liquid, and the atmospheric air from without entered the flask through the sulphuric acid. The air was of course not at all altered in its composition by passing through the sulphuric acid in the flask; but all the portions of living matter, or of matter capable of becoming animated, were taken up by the sulphuric acid and destroyed. From the 28th of May until the beginning of August, Professor Schulze continued uninterruptedly the renewal of the air in the flask, without being able, by the aid of the microscope, to discover any living animal or vegetable substance; although, during the whole of the time, observations were made almost daily on the edge of the liquid; and when, at last, the Professor separated the different parts of the apparatus, he could not find in the whole liquid the slightest trace ofInfusoriaorConfervæ, or of mould; but all three presented themselves in great abundance a few days after he had left the flask standing open. The vessel which he placed near the apparatus contained on the following dayVibrionesandMonads, to which were soon added larger PolygastricInfusoria, and afterwardsRotifera."—pp. 32, 33.
"He filled a glass flask half full of distilled water, in which were various animal and vegetable substances: he then closed it with a good cork, through which were passed two glass tubes, bent at right angles, the whole being air-tight: it was next placed in a sand bath, and heated until the water boiled violently. While the watery vapor was escaping by the glass tubes, the Professor fastened at each end an apparatus which chemists employ for collecting carbonic acid: that at the one end was filled with concentrated sulphuric acid, and the other with a solution of potash. By means of the boiling heat, it is to be presumed that every thing living, and all germs in the flask or in the tubes were destroyed; whilst all access was cut off by the sulphuric acid on the one side, and by the potash on the other. The apparatus was then exposed to the influence of summer light and heat; at the same time, there was placed near it an open vessel, with the same substances that had been introduced into the flask, and also after having subjected them to a boiling temperature. In order to renew constantly the air within the flask, the experimenter sucked with his mouth several times a day the open end of the apparatus, filled with the solution of potash, by which process the air entered his mouth from the flask through the caustic liquid, and the atmospheric air from without entered the flask through the sulphuric acid. The air was of course not at all altered in its composition by passing through the sulphuric acid in the flask; but all the portions of living matter, or of matter capable of becoming animated, were taken up by the sulphuric acid and destroyed. From the 28th of May until the beginning of August, Professor Schulze continued uninterruptedly the renewal of the air in the flask, without being able, by the aid of the microscope, to discover any living animal or vegetable substance; although, during the whole of the time, observations were made almost daily on the edge of the liquid; and when, at last, the Professor separated the different parts of the apparatus, he could not find in the whole liquid the slightest trace ofInfusoriaorConfervæ, or of mould; but all three presented themselves in great abundance a few days after he had left the flask standing open. The vessel which he placed near the apparatus contained on the following dayVibrionesandMonads, to which were soon added larger PolygastricInfusoria, and afterwardsRotifera."—pp. 32, 33.
For readers who are not familiar with these subjects, it may be well to mention, that the weight of authority is decidedly against this doctrine of spontaneous generation. It isrejected by Müller, who ranks among the first physiologists of Germany; by Ehrenberg, one of the most distinguished microscopists in the world; and by Owen, who stands at the head of the school of comparative anatomy in England, if not in Europe. The remark made by Cuvier, more than thirty years ago, is still true at the present day, that, "although the impossibility of spontaneous generation cannot be absolutely demonstrated, yet all the efforts of those physiologists who believe in the possibility of it have not succeeded in showing us a single instance."
Passing over, then, our author's theory of the origination of life from inorganic matter as utterly untenable, we come to the next point in his system,—the most chimerical of all,—the gradual development of the higher orders of being out of those next beneath them in the scale. It is not pretended, that there isany known instanceof the transmutation of species, or of the evolution, in the ordinary way, of any being specifically different from its parents. The same animal, indeed, may pass through different grades of development; but these changes affect only the individual, not the race. The progeny of this animal must begin at the same point where its parent did, and run precisely the same cycle. The tadpole becomes a frog, but the young of that frog are tadpoles; the worm becomes a winged insect, but the eggs of that insect are hatched into nothing but worms. These changes in the life of the individual, like the successive periods of the embryotic state, of infancy, and manhood in the human being, are perfectly consistent with persistence of type in the race, and do not indicate even the possibility that a new species may be developed out of an old one. On the contrary, the germ must be considered aspotentiallyequivalent to the whole future being, for it is invariably developed into that being. If there be any one fact unquestionably established by observation, it is that each species invariably produces its like. "All the phenomena," says Müller, "at present observed in the animal kingdom, seem to prove that the species were originally created distinct, and independent of each other. There is no remote possibility of one species being produced from another."
The doctrine of our author, then, is confessedly a pure hypothesis, and, as such, it might be summarily dismissed into the region of cloud-land and dreams, where it had itsorigin. The burden of proof is upon him, and as he has failed to produce a single instance in which his theory is exemplified, he may be rightfully debarred the privilege of discussion. But waiving this point, if we look into the grounds of his conjecture, we find bold assumptions more than once substituted for the plain statement of facts, which would destroy every shade of credibility in his doctrine. True, there is an appearance, both in the animal and vegetable kingdoms, of an ascending scale of being, from simply organized forms and imperfect developments up to the complex arrangements and nice adaptations of the advanced tribes. But the progress is not regular, nor are the intervals of constant length. The line is often broken and doubled, and, in fact, the individuals are far more naturally arranged in a number of parallel lines, beginning successively at a somewhat lower point, than in a single series. Man, of course, is placed at the head of the animal tribes; but the interval which separates him from the chimpanzee cannot easily be cleared at one bound. He forms but one genus, and that genus is the only one of its order. But even if the line of gradation were single and perfect, the fact would be of no service to the hypothesis we are now considering; for the interval between two species most nearly allied to each other seems to be quite as impassable as the broadest gulf of separation.
The point chiefly relied upon to show the credibility of this doctrine is the fact, according to our author, that the higher animals pass through a series of changes resembling the permanent forms of the lower tribes. The first form of man himself "is that which is permanent in the animalcule"; and thence he comes to resemble successively a fish, a reptile, a bird, and the lower mammifers, before he attains his specific maturity. It is held, then, that a premature birth from an animal of a higher kind might have instituted a new race of a lower type; and that a birth unusually delayed, permitting an embryo to be still farther advanced in the line of organization, might have created a new species of a higher order than the parent. Here, every thing depends on theabsolute identityof the germs of all animals, in the lower stages of their growth. General resemblances and analogies are of no weight whatever; the essential internal organization of the ova of different species must be the same; otherwise, however ripened into a mature being, whether the birth beadvanced or postponed, the individual must still belong to its parents' species, of which it possesses the distinctive peculiarity. Now, this point ofthe identity of germs is a mere assumption; not only is it destitute of proof,—the whole evidence is against it. There is a degree of outward resemblance, but there is no sameness. When we trace the origin of life back to the remotest point to which our powers of observation extend, when we come to microscopic vesicles that can be discerned only by the highest magnifiers, general similarity of outward shape is all that can be predicated of them. The specific differences lie below this general resemblance of outward form; we cannot discern them, but weknowthat they must exist, and that they areessentialdifferences, for each one of these vesicles is invariably developed, if at all, into an individual of the species to which its parent belongs. The germinal vesicles of a tree and a quadruped are somewhat alike, outwardly; so, to the hen's eyes, there is no difference between her own eggs and the duck's eggs which the farmer's wife has put into her nest. But when she has hatched her brood, part of them are found to be web-footed, and these, to her great astonishment and distress, immediately take to the water. Our author commits the same blunder as the poor hen. This want of consciousness that he has got to the end of his tether, this inability to believe that any difference can exist where he is not able to see it, though it is invariably indicated by future consequent differences of the most striking nature, is perfectly characteristic of the rash theorist in science.
The assertion, that man's "first formisthat which is permanent in the animalcule,"—even if we do not look to the potentiality of development into a higher being, which experience shows to exist in the human germ, but not in the infusorial,—is a positive misstatement. The lowest monad has a mouth and means for propagating its kind, which do not belong to the primitive ovum of any higher animal. About the succeeding stages in the growth of the embryo our author's language is more cautious. He only says, that theyresemble, ortypify, some of the lower orders of being; and this is virtually admitting a specific difference, and giving up his own theory for all the conditions posterior to that of the germ. The brain and heart of the embryo successivelyresemblethe corresponding organs in a fish, a reptile, a bird,and a quadruped; but they are not identical,even in outward appearance, with those organs. Of course, if arrested at any stage of its growth, and prematurely born, the embryo would not be one of the lower animals, but only something resembling it in outward shape; and conversely, if it were possible for the birth of a bird to be delayed till it had reached a higher stage of development in the same line in which it was proceeding, it would not become a quadruped, but it would be an anomalous creature somewhat like one. Consequently, no one species now on the earth can have been evolved out of any other existing race; because the germs of any two, at a very early stage in their history, according to our author's own confession, are specifically unlike.
To avoid this difficulty, he is driven to a further supposition, still more gratuitous and improbable; namely, that the germ destined to become one of a different race from its parents, having advanced along its usual line of development so far as that line coincides with the one belonging to the new species, there diverges, and follows a different path up to the period of its birth into a new creature; that is, the embryo of a reptile, having grown for a certain time as if it were to be a reptile, suddenly turns aside, like a young man changing his mind about the choice of a profession, and for the rest of its fœtal life follows the proper line of progress in order to be developed into a bird. This is mere dreaming, and reminds one only of the wonderful transformations effected by enchantment in an Arabian tale. We might just as plausibly suppose, that the reptile, after it became mature, was suddenly transformed into a bird, as that it underwent this change before it was hatched. All the evidence attainable goes to show, that the law of development is as immutable before as after birth, the several stages of progress succeeding each other in a constant order, and affecting the individual only, not the race. A young monkey is no more likely to be transmuted into a man than an old one; nor is such a metamorphosis at all more probable in the course of its fœtal life.
The view we have now obtained of the specific differences between distinct races of being at separate periods of their existence is precisely what might have been anticipated from the law of gradual development, which holds throughout the organic kingdoms. Between two mature animals, thesedifferences are perfectly obvious and well marked. As we go a step back in their history, the distinction becomes a little more obscure; two worms may resemble each other very closely, though the two winged insects subsequently produced from them may be very unlike. Receding still farther, some of these specific differences may entirely disappear, the organs or parts which should exhibit them being not yet developed. And when we come to the primitive germs, so minute as to be visible only through the microscope, no outward distinction, perhaps, is any longer perceptible, and the radical difference of their internal organization is indicated only by the fact, to be verified by subsequent observation, that the two are invariably developed into perfectly distinct animals, belonging respectively to the same races with their parents. A theorist, whose whole system is based upon the invariable operation of natural agencies, cannot reasonably object to this conclusion.
That our statements in the course of this argument may not appear of the same questionable character as those advanced by our author, we will fortify them with a few brief citations from a work of such unquestionable authority as the Lectures of Professor Owen.
"No doubt the minute infusoria, which seem to have their development arrested at the first or nearest stage from the primitive cell formation, offer close and striking analogies to the primitive cells out of which the higher animals and all their tissues are developed; but the very [first] step which the infusoria take beyond the primitive cell stage invests them with a specific character as independent and distinct in its nature as that of the highest and most complicated organisms. No mere organic cell, destined for ulterior changes in a living organization, has a mouth armed with teeth, or provided with long tentacula; I will not lay stress on the alimentary canal and appended stomachs, which many still regard as 'sub judice'; but the endowment of distinct organs of generation, for propagating their kind by fertile ova, raises the polygastric infusoria much above the mere organic cell."—pp. 25, 26."In comparing the several stages in the very interesting development of thecyanæa auritato the infusoria and polypes, it must be understood that such comparisons are warranted only by a similarity of outward form, and of the instruments of locomotion and prehension. The essential internal organization of thepersistent lower forms of thezoöphytais entirely wanting in the transitory states of the higher ones. A progress through the inferior groups is sketched out, but no actual transmutation of species is effected. The young medusa, before it attains its destined condition of maturity, successively resembles, but never becomes, a polygastrian, a rotifer, and a bryozoon."—p. 112."Thus every animal in the course of its development typifies or represents some of the permanent forms of animals inferior to itself; but it does not represent all the inferior forms, nor acquire the organization of any of the forms which it transitorily represents. Had the animal kingdom formed, as was once supposed, a single and continuous chain of being, progressively ascending from the monad to the man, unity of organization might then have been demonstrated to the extent in which the theory has been maintained by the disciples of the Geoffroyan school."—p. 370.
"No doubt the minute infusoria, which seem to have their development arrested at the first or nearest stage from the primitive cell formation, offer close and striking analogies to the primitive cells out of which the higher animals and all their tissues are developed; but the very [first] step which the infusoria take beyond the primitive cell stage invests them with a specific character as independent and distinct in its nature as that of the highest and most complicated organisms. No mere organic cell, destined for ulterior changes in a living organization, has a mouth armed with teeth, or provided with long tentacula; I will not lay stress on the alimentary canal and appended stomachs, which many still regard as 'sub judice'; but the endowment of distinct organs of generation, for propagating their kind by fertile ova, raises the polygastric infusoria much above the mere organic cell."—pp. 25, 26.
"In comparing the several stages in the very interesting development of thecyanæa auritato the infusoria and polypes, it must be understood that such comparisons are warranted only by a similarity of outward form, and of the instruments of locomotion and prehension. The essential internal organization of thepersistent lower forms of thezoöphytais entirely wanting in the transitory states of the higher ones. A progress through the inferior groups is sketched out, but no actual transmutation of species is effected. The young medusa, before it attains its destined condition of maturity, successively resembles, but never becomes, a polygastrian, a rotifer, and a bryozoon."—p. 112.
"Thus every animal in the course of its development typifies or represents some of the permanent forms of animals inferior to itself; but it does not represent all the inferior forms, nor acquire the organization of any of the forms which it transitorily represents. Had the animal kingdom formed, as was once supposed, a single and continuous chain of being, progressively ascending from the monad to the man, unity of organization might then have been demonstrated to the extent in which the theory has been maintained by the disciples of the Geoffroyan school."—p. 370.
If these similarities of structure in the germ had any bearing on the subject, they would indicate the possibility only of retrogression in the scale. Of course, the immature ovum, arrested in its development, could not form a more perfect being than its parent. There is no pretence that the embryo, at any stage of its progress, images an animal of a higher grade than its own family. Then what aid do these similarities of structure afford to the theory, that all the higher organisms have been evolved by successive steps out of the lowest monad? At the best, you have only shown, that aretreatis possible; you have still to point out any likelihood, even the remotest, of anadvancein the scale of being. There is no fact whatever to confirm the supposition, that birth may possibly be delayed till the animal be developed into one of a higher species; and the law of immature births seems to be, that, if the offspring escapes at all—for there is great risk consequent on such an accident,—it becomes as perfect as its progenitors. Nature seems to guard the distinctions between the several races with peculiar care; so far as we know, monsters either do not survive their birth, or are incapable of continuing their kind, or in the course of a single generation are reunited to the original family.
To say that these laws, distinct and invariable as far as the observation of man has extended, may possibly have been superseded in the lapse of ages by a higher principle, manifestingitself only at long intervals, is again to have recourse to a blank hypothesis, incapable alike of proof or disproof, and unsupported by the faintest intimations from the world of experience. To build up a theory in this way is not to account for the work of creation by the natural agencies and inherent qualities of matter,as at present observable, but to fly off to the wild supposition, that matter and life were more richly endowed ages ago than they are in our own day. You affirm, that this higher principle of development did not override the inferior laws at the earlier periods in time's history, because, in the infancy of the universe, the conditions were wanting which are requisite for its manifestation,—because the earth was not ready, the atmosphere was not purified, for the nobler races of being. Very well; but these conditions are answerednow. All things are ready at the present day for the innate energies of matter to put forth their utmost strength. Why do not fishes generate reptiles, and birds produce mammifers,now? Ah! but "the earth being now supplied with both kinds of tenants in great abundance, we could only expect to find the life-originating power at work in some very special and extraordinary circumstances." It seems, then, that these inherent qualities of matter, once supposed to be blind, absolute, and invariable in their operation, are really very judicious and reasonable; they suit the supply to the demand, and actually cease working when the market is likely to be overstocked. The results of such "naturalagencies" as these are very like the effects produced by the volitions of a wise and thinking being.
It happens that we are not obliged to grant to our author an indefinite lapse of ages for the sake of bringing all his higher principles into action. One of the latest events in the geological history of the earth was a great submersion of the land, by which "terrestrial animal life was extensively, if not universally, destroyed"; so that the creation of the species now in being—at least, all the higher species—was "a comparatively recent event, and one posterior, generally speaking, to all the great natural transactions chronicled by geology." Science does not contradict, it rather confirms, that voice of revelation or tradition, which assigns about six thousand years as the period of man's residence upon the earth. The action of the drama, then, is restricted withinmoderate limits as to time, and the "natural agencies" and "higher principles" must work fast in order to accomplish their task within the prescribed period. One condition for the creation of a new and permanent species, belonging to any of the higher orders, seems to have escaped our author's notice; at least two individuals, a male and a female, must have been evolved out of the next lower race, before the new species could continue its kind. Apply these considerations to the creation of man, who, according to our author's Scripture, was born of a monkey. To suppose, that, at the first trial, an Adam and an Eve were born near each other, so that they might have a chance of meeting in the course of their lives, would look too much like the operation of intelligence and design. On the theory of an organic creation by law, as the monkey race is spread over large regions of the globe, we must suppose that many of each sex were produced, and died childless, before any Adam was happy enough to find an Eve. Then, at no very distant period, within a few thousand years, the birth of a man from an animal of a lower type was no very strange event. Probably it occurred so often, that the monkeys themselves ceased to be astonished at it. And yet, this tribe of animals, with all the benefit of large experience, with increased numbers, and with all the requisite conditions fulfilled at least as perfectly as they were at the earlier period of their history, have not succeeded, in the three or four thousand years during which they have been subject to the observation of intelligent beings, in producing even a decent semblance of a man.
With the exposure of this crowning absurdity, we must close our direct examination of this "History of Creation." We have not room to consider some of the appendages to the theory, such as the assertion of the essential unity of the human and the brute intellect, the denial of the immaterial nature of mind, and the advocacy of the system of phrenology. These absurd and degrading doctrines are naturally connected with the atheistic hypothesis we have been considering. They are its legitimate children. But they have already been refuted so often and so conclusively, that any revival of them at the present day is hardly deserving of notice. If we should stop here, then, it may fairly be left to the judgment of our readers, whether we have not fulfilled the pledge given at the outset, by showing that this theory isfaulty at every point, even when viewed from the author's own ground. The proposal of it is no new thing. In one or another form, varying in particulars, but agreeing in substance, it has been before the world ever since the days of Democritus, and more especially of his follower, Epicurus. Lucretius clothed it in sonorous and majestic verse, for it is a theme fitted above all others to excite the fancy, and to receive the richest embellishments from the imagination. Modern authors have promulgated it again and again, with little other change than what was requisite to adapt it to recent improvements in science, and to engraft upon it some of their own favorite hypotheses and fancies. The version of it by the French naturalist Lamarck was the latest and the most in vogue, till the appearance of the present volume. So frequently has it been confuted, that the revival of it at this late period seems little more than a harmless exercise of ingenuity, a poetical and scientific dream, and one need hardly take the pains to expose its assumptions and fallacies. The violent suppositions which it involves only remind one of the remark quoted from Pascal on a former page, that "unbelievers are the most credulous persons in the world." If set forth only as a novel and pleasing fancy, it may be classed with other ingenious fictions, that are published without a thought of deception. But if seriously proposed, it can be fitly characterized only by borrowing the homely but energetic language of Dr. Bentley.