# Scientific Memoirs/1/The Kingdoms of Nature, their Life and Affinity

From the Zeitschrift für Natur und Heilkunde, Band i. Hefte i. Dresden, 1819.
Article X.
The Kingdoms of Nature, their Life and Affinity; by Dr. C. G. Carus.
From the Zeitschrift für Natur und Heilkunde, Band i. Hefte i. Dresden, 1819.
When man awakes from that state in which he is but the passive recipient of impressions from the external world, and when therefore, instead of reposing in the consciousness of his increasing in strength and stature and exhibiting a reciprocity of bodily action of various kinds with surrounding objects, he feels the spirit, the infusion of the breath of God, in motion within him, he is powerfully impelled to endeavour, by bringing the relations between the spirit within and the phænomena without into a clear point of view, to obtain a clearer knowledge of himself. This desire has its origin in a most distinct conviction that without such knowledge no real harmony, no true internal equilibrium can be conceived to exist in man, and that nature and he must therefore stand as two eternally separated beings. But a feeling that things are separated which at the same moment exist in and through each other, is totally incompatible with that internal repose which, as we ourselves are one, is to be found not in the sense of separation but in the consciousness of unity. In this fact we clearly see what it was that gave birth to those speculations, by means of which it was sought for so many ages, sometimes with more and sometimes with less sincerity and freedom, to ascertain the relations between the phænomena of nature and the laws of mind. In those speculations, however, we have occasion to observe, how frequently that which stands forth in us most plainly and undisguisedly, and which for that reason should be supposed discernible and known at the very first, was exactly the least heeded and last discovered. It was, no doubt, owing to this circumstance, that many a truth which presented itself almost unveiled to the pure and unsophisticated feeling of the genuine children of nature remained a hidden mystery to the sages of mankind.
In order to avoid such errors it is particularly important that we should give a general and exact definition of the terms proof and explanation. Now to explain is but to consider a phænomenon in the clearness of a superior light, and to prove is but to trace a subordinate proposition up to a higher, or rather to a primary truth. The supreme and one, which is alike the foundation of nature and mind, can therefore no more be proved or explained than the splendour of the sun can be increased by means of some terrestrial light. On the contrary, the ​immediate consciousness of a supreme and eternal unity is the primary standard by which we distinguish the just, the true, and the beautiful. Without this principle we should indeed be incapable of pursuing any general inquiry and of forming any judgement, so that demonstration and science can exist for those only who recognise a positive and supreme principle. We hold, therefore, that the true end of scientific inquiry (so far as it is to furnish explanation) is not to define and demonstrate the highest principle, but to trace other truths up to this, to show the harmony which, exists between nature and mind, or to discover a unity of law in the multiplicity of phænomena.
It is hoped that these general remarks may be sufficient to indicate the guiding principle of the following inquiries, which, being designed to lead to a clear conception of Life in general, and its single forms in particular, are here recommended by their author to the friendly attention and examination of medical men and naturalists, previously to their being, perhaps, at some future time, presented by himself or by some one else, in that strictly scientific form which is found so indispensably necessary to all who would penetrate the essence of nature, and obtain, instead of the vague and negative notions which commonly prevail, a distinct and positive knowledge.
If, with this view, we direct our attention to one only of the endless variety of forms which life assumes; if we observe, for instance, how a plant through internal instinct and under external relations unfolds itself from an obscure and insignificant seed, how its parts multiply, and how their organization becomes progressively more and more refined, until it reaches its acme in the flower, where the plastic power again concentrates itself into a seed, and thus closes the circle of its being in that form out of which it had first issued, we find throughout this chain of phænomena an internal pervading principle, a certain determinate succession, a regularity which compels us to expound all these movements, changes, and developments as parts of a whole, as the operations of one internal universal cause in which all others are comprehended. It is evident that this internal, this essential and efficient principle can be no single thing, such ,as the body of the plant, the chemical change of its substance, or the circulation of its sap, and still less the effect of external influences, but rather all these together—a something in which all these inhere as their common cause, and which we characterize as a unity by the generic appellation life. Hence it is easy to perceive how erroneous it would be, for instance, to suppose the plant first organized, and life then added to it as an attribute and consequently as something extrinsic, nearly in the same manner as we should conceive of a machine as a thing consisting of several parts put together and possessing, at first, no inherent power of acting, but having this power imparted to it when it is completed. On the contrary, life is necessarily the original principle, and the body one of its particular ​phænomena, conceived therefore not as permanent but as perpetually changing; and this idea of it is conveyed in the term formation, inasmuch as it signifies a thing not only formed but forming itself. We know, for example, that the human body after a series of years is a very different thing from what it was at an earlier period; nay, that the body of the adult does not contain even a single atom of that which constituted the fœtus; and nevertheless, that the internal, the living principle, the man, as every one's consciousness undeniably assures him, is still the same, nothing being changed but the phænomena of life, among which, as we have already shown, the body is to be included.
As it follows from the foregoing observations that life is not a single isolated reality, we shall be obliged to define it generally as the constant manifestation of an ideal unity through a real multiplicity, that is, the manifestation of an internal principle or law through outward forms. This view of the subject will indeed derive additional light from the analogous character of that inward principle which we call soul, inasmuch as this also consists not in this or that particular thought, or in the mere succession of our thoughts, or anything else of the sort, but in the whole spiritual life in general, that is, in the constant revelation and manifestation of an internal unity—of the deepest consciousness of the individual identity through an infinite variety of sensations and ideas.
If we now cast a look on that universal nature which surrounds us, the endless multiplicity of its phænomena is indisputably manifest; and as it would be an absurdity to imagine a highest number to which another number cannot be added, we can fix the limits of nature nowhere, either in the great or in the small, because the infinite divisibility of each would lead again to infinity. These infinities are nevertheless included in the comprehensiveness of the whole; there is but one whole, (the word has no plural form in our language,) and the idea of this necessarily contains at the same time the internal multiplicity, or rather infinity; for it would be a manifest inconsistency to conceive of a real whole as a unity, while in its strict reality it implies rather the idea of an infinity of individuals. Thus we find in fact the idea of life, that is, the constant manifestation of unity through multiplicity, exhibited by universal nature; and are therefore bound to consider nature collectively as one vast and infinite life, in which, though the extinction of any one of its various modifications, or the merging of a single external form of life in the universal life, is possible, an absolute and proper death is inconceivable.
Proceeding from this general view to the consideration of single beings, we perceive that all those individuals, so far as they are integrant parts of universal nature, must partake more or less of its essential properties,—that whatever is essential to the one must be partially repeated in the other. Every natural being must therefore appear, like nature in general, partly as a unity (in which light only it is an individual), and partly as a multiplicity, in which light it is infinitely ​divisible, and its action and reaction upon the different other individuals may also be infinite. At the same time it still further appears that such an individual approaches more nearly to general nature in proportion as the multiplicity manifesting itself in its unity is more comprehensive and striking. A substance therefore (a geometrical body, for instance,) which is merely multiform and infinitely divisible in space but immutable in time, has far less claim to this affinity than a body, such as that of a plant or an animal, which changes in time also because of its continued growth and progress toward an independent life. Although, as has been shown already, the idea of life is in full and perfect accordance with universal nature, and consequently no natural body can, in this general view, be accounted anything more than a living member of the whole, yet there is a vast difference perceptible between individuals, inasmuch as the collective idea of life, a life proper to themselves, manifests itself in some, while others are less independent and can be recognised only as necessary parts of other individuals.
Now it is clear that the idea of life and that of an organism are essentially the same; for any unity that continually develops itself inwardly and outwardly into a real multiplicity is named—so far as it produces means, that is to say, instruments or organs suited to its own development—an organism or organized body, and everything belonging to it is termed organic. Its action is therefore named organic life, and that which is generated in space by this living action the organic body. Universal nature is consequently to be considered as the highest, the most complete, the original organism; and in nature those individuals only are to be called organisms which, as unities under certain external conditions, that is in their relation to other natural unities, continually develop themselves inwardly and outwardly into a real multiplicity. Among such organisms the most prominent are those bodies which, including our planet, constitute the system of the universe, and display themselves in continual motion and formation; those on our planet consist of plants and animals.
Now, as in an animal a piece of bone, muscle, or skin, and in a plant a fragment of the wood, leaf, or fruit, may be considered as organic, but cannot be called an organism, all substances, except plants and animals, observable in and upon the body of the earth, so far indeed as they are parts of the terrestrial organism, are to be regarded as organic and as parts of a living thing, but not as organisms possessing an independent life.
According to this view we must include among those things which do not as unities develop themselves into multiplicity,—that is, among ​Inorganisms,—1st, all substances which, though infinitely divisible, being but mechanically so, are incapable of being developed into various parts and of maintaining at the same time their individual existence; and therefore all elementary bodies, such for instance as oxygen, hydrogen, carbon, the metals, sulphur, &c. 2nd, All substances whose resolution or development into their elements annihilates their individual existence; as, for instance, water, which, as soon as it is decomposed by the influence of galvanism into oxygen and hydrogen gas, ceases to be water,—widely differing in this respect from the plant, which, when it develops itself into leaves, branches, flowers, and fruit, remains still the same plant, or rather becomes then for the first time completely a plant. To these we must add the acids, salts, &c., nay, the constituent parts of organic bodies themselves, which being resolved into their elements are, as organic bodies, utterly destroyed. 3rd, All bodies which owe not their existence and multiplicity to spontaneous development, but are composed by nature or by art out of materials already prepared; for instance, floating islands, buildings formed by animals, all automata, machines, &c.
But as we find in real organisms single subordinate parts or organs, which in a certain degree reproduce the idea of the whole; nay, as we see that in less perfect organisms that bond of unity which holds the developed parts together is yet so feeble that if it is separated the part appears to be really a whole, (for instance, the shoot of a plant separated from its parent often becomes a new plant, and the parts of a polypus become new polypi,) so do we not unfrequently observe the idea of the living thing to which they belong reproduced to a certain extent by natural bodies which, so far as they are parts of a greater organism, have not the appearance of being organisms themselves. Of this fact we have an instance in the formation of a water-drop, which, as manifesting a certain force of gravity or tendency to internal unity, is essentially analogous to the spherical formation of the heavenly bodies; and in crystallization, the growth of metals, &c. we see a repetition of the process by which the earth was formed out of fluids. If we turn our attention to these intimations of individual life in unorganized bodies, the idea of the living principle pervading all nature presents itself anew and more distinctly to our minds, and we are forced to admit the relations of the unorganized to organized bodies, which could exist only in this connexion and under their other relations to universal nature. From all this we are finally led to infer the universal connexion, the combination, the never-ceasing action and reaction of all the powers of nature, sometimes in sympathy, sometimes in antipathy, as necessary to the production of an immeasurably vast and magnificent whole,—an action and reaction which would be impossible, were not all originally pervaded by one living principle, were not all in this respect similar and allied to each other.
​From these general conclusions we proceed to a survey of the different kingdoms of nature, in order to submit to a closer examination the peculiarity of their life and their mutual relations. For this purpose we must define more exactly the boundaries of each separate kingdom. Here we must first make a distinction between the celestial and the terrestrial bodies. To the former belong the solar systems, including the earth considered as a planet. The idea of terrestrial bodies comprehends all the different single objects perceptible by the senses in and on the earth. Now, terrestrial bodies, according to their appearing or not appearing as independent organisms, form two principal classes, and this leads to a second division of bodies into the organized and unorganized. We divide the inorganic bodies likewise, as far as we consider them members of the planet, into the constituent parts of the body of the earth, and the constituent parts of the atmosphere, viz. 1. Fossils and liquids; 2. Gases and vapours. The organic bodies are divided into vegetable and animal bodies. We have therefore four kingdoms of nature, and four different departments of natural philosophy belonging to them. The kingdom of the earth (Geology); the kingdom of the air (Atmospherology); the vegetable kingdom (Phytology, Botany); the animal kingdom (Zoology).
Of the Inorganic Kingdom.
The great elementary masses of the earth are formed and governed by many powers, among which we may distinguish those which relate to the individual preservation of the planet, from those which originate in other heavenly bodies. Of the former the most remarkable is Gravitation, which manifests itself as the immediate principle of internal unity, the sensible tendency of all parts of the earth to a common centre, and therefore to an ideal unity, since according to Euclid no point can be represented materially. But another effect presenting itself in the visible relation of the earth to other heavenly bodies, is that which we perceive under the form of Light. These two powers, when united, produce other phænomena; for instance, heat, which results from the opposition between the rays of light and the direction of gravity: wherefore we observe the heat of the earth to be more intense, the more the heated body is found to be in a straight line between the illuminating and the illuminated object, that is, between the centre of the sun and that of the earth. To these also belongs the phænomenon called magnetism, as the effect of the gravitation of the earth, and its position with respect to the other planets, i. e. the direction of its axis. In heat the predominant principle is light; whereas the predominant principle in magnetism is gravitation. To these we find new powers still added, among which the mechanical and the chemical appear to be allied to gravitation and magnetism, (for the laws of mechanics are ​essentially connected with those of gravitation, as the chemical laws include the compositions and decompositions, the attractions and repulsions of ponderable bodies,) while electricity and galvanism, on the contrary, being more connected with light and heat, are found less inherent in terrestrial substances. A body which is an electric or galvanic conductor can be conceived to exist without electric or galvanic power; whereas no earthly substance can be imagined without the chemical effects proper to its composition, and the mechanical operations proper to its form. It is moreover worthy of remark how all this series of powers, which constitute in their totality the life of the planet, is found also in its single parts constantly and in the most various forms; for we find in every object a proportionate gravitation of the mass toward its centre. This fact explains the mutual attraction of two bodies floating in a fluid, the formation of a drop of water, and the nature of the globular form in general as one in which all the radii, or the relations of the periphery to its centre, are equal. It explains also the mutual illumination of single terrestrial bodies; the production of heat as the result of the collision of different bodies; the manifestation of electricity, not only in the stormy atmosphere, but also in resin and glass; and the manifestation of terrestrial magnetism in the smallest bar of iron. These objects, for the complete examination of their endless variety and eternal regularity, require a full development of the laws of chemistry and natural philosophy,—a development which would exceed the limits of this treatise as much as it does the powers of the author, and which, in its full and scientific comprehensiveness, is still a desideratum.
But our purpose demands a particular examination of the relation of water to the other atmospherical and terrestrial substances, more particularly because it forms, as we shall show, the most essential link between organized and unorganized bodies, or rather the constant source from which the former arise. Water considered in its threefold form, as solid, fluid, and gaseous, presents a true middle and connecting member between the planet and its atmosphere. It may be considered as the indifference of both,—on which fact depends its decomposition into a combustible element (hydrogen), and an element promoting combustion (oxygen), nay, it is in its purity really indifferent in respect to the other terrestrial as well as to atmospherical substances. But the manifold in nature, however far back in point of time we trace its origin, will be found constantly issuing out of the simple and indifferent; and on this very account water, as far as it appears an indifference, becomes the germ and source of an infinity of other forms; indeed it is a question whether we are not already justified in supposing, and whether further inquiries will not establish the fact, that both the planet and its atmosphere are but different developments of one and the same original fluid. Several, of the older chemists (Leidenfrost, Wallerius, Markgraff) have attempted to show, that even ​now, during certain chemical processes, particles of water are changed into earth; and though Lavoisier has sufficiently refuted that opinion, he has not demonstrated the impossibility of the decomposition of an original fluid into water, air, and earth. That water is of the utmost importance in the general formation of the earth, has been proved beyond doubt by the excellent experiments of the immortal Werner; and we are justified in continuing still to believe in its importance to the preservation and life of the planet, when we take into consideration both its quantity and its continual motion. In regard to its quantity, we find that of the sum total of the surface of the globe (9,000,000 square miles,) the water occupies nearly 6,500,000 and the land only 2,500,000. The water is so deep also that several points of the sea are unfathomable, although latterly it has been fathomed to a depth amounting to 4600 feet. The motion of the water, on the other hand, depends partly on gravitation, as in the running of rivers and streams; partly on the attraction of other planets, (viz. the sun and moon,) as in its ebbing and flowing in the tides, and in its ascending and descending between the earth and sky in the form of vapour, dew, rain, snow, &c. Comparing animal with planetary life, we are therefore led to conclude, that as a homogeneous fluid, in continual circulation, the blood, is the source in which all forms and reproductions of the organism originate, so is water one of the members most important to the life of the earth. This internal life of the fluid becomes indeed more evident when we consider the individual formations of the solid to which it gives birth. The most striking illustration of this is the process of crystallization, which exhibits a near approach of the inorganic to the organic life; for we cannot deny, even to the crystal, a certain inward peculiar life at the moment of its formation. The only difference between an organic body and a crystal is, that the life of the latter, the principle of action and reaction, terminates as soon as its formation is accomplished. One might be tempted to say that the crystal lives only to form itself; for as soon as it is formed it dies; while true organisms, on the contrary, form themselves only in order to live, and it is only when they are perfectly formed that their life is truly and properly evident. But the formation of the crystals, as a process nearly allied to organic life, is not the only phænomenon remarkable in them. The very forms of the crystal are, in their approximation to the form of the organized being, well worthy of a closer attention. We find in all earthy, as well as in many metallic or combustible fossils, the purely geometrical form of the crystal, which, in proportion as it is more compact, and presents a more limited coincidence ​of surface with other forms, approaches more nearly the spherical form, as that which is perfectly compact, thoroughly symmetrical, and therefore fundamentally organic. The icosahedron, for instance, approaches the spherical form more nearly than the octahedron does; it is also important to observe that the most precious crystals, and especially the diamond, (which being pure carbon, is therefore, from its composition, most closely allied to the organized bodies,) are those wherein we observe the most compact crystallization, at least that which approaches most nearly to the sphere and is therefore in nowise columnar; wherefore the diamond, particularly on account of its power of refraction, has a closer resemblance to a solid drop of water. This view, by showing how crystallization may be examined, from the three-sided pyramid and the cube upwards to the most many-sided forms, or those which approach nearest to the sphere, may place the theory of crystallization on a more natural and therefore a more philosophical basis. On the other hand we must also take into consideration the copies, or rather the prototypes, of the form of really organized bodies which occur in the solidification of the fluid. It is by no means without a cause, nor to be regarded as a mere lusus naturæ, (a very unmeaning expression,) that pure water in its crystallization assumes forms which correspond most closely with those of inferior organizations: thus the flakes of snow represent the forms of Polypi, Asteriæ, and Medusæ; we find in the ice on windows the forms of many vegetable substances, leaves, stems, flowers; the earth too and some metallic substances present, when melted or united with water, similar types, in which we see the condition under which Dendrites and the manifold forms of native ores originate. In all this the moving creating life of the original fluid cannot pass unnoticed, and becomes still more evident if we examine the history of the origin of organized bodies, in which the fluid appears as the basis both of animal and vegetable life; and thus the very germ of individual organisms is intimately connected with the life of the planet. Indeed this is partly true of the solid parts of the earth; for it is easy to show, even in the fossil kingdom, a transition partly to animal and partly to vegetable life; so much so, that a philosophical inquirer, Henry Steffens, has been led, from a comparison of several facts, to establish two very probable propositions relating to this subject:
"1. In the whole silicious series (of fossils),—which constitutes the chief mass in the oldest and principal mountains of our earth, which goes through all periods, and in its bituminous substances exhibits the remains of an extinct vegetation, yet connected as a living member with the whole existing vegetation by the marsh-turf,—carbon and hydrogen (the essential elements of the vegetable kingdom) are the principal ​characteristics. 2. In the whole calcareous series,—which begins in the oldest mountains of our earth, proceeds through all periods, is of the greatest magnitude in those of the latest formation, presents in the petrifactions the relics of an extinct animalization, and is connected as a living member (in the coral-banks), with the existing animal world,—nitrogen and hydrogen (the essential elements of the animal world) are the principal characteristics.
The connexion between inorganic and organic life, however, is shown more immediately and more clearly in the production of organisms from pure water; to which we must refer both the origin of the Infusoria obtained by the pouring of water over mineral substances, as observed by Gruithuisen, and still more, the origin of the so-called green matter, the history of which has been so admirably traced by Priestley and Ingenhousz. These show more than all other experiments, that in the purest water, under the free influence of air, light, and heat, beings are formed which, oscillating as it were between the animal and the plant, exhibit the primitive germs of both kingdoms. The succession of the changes which take place in the formation of the Infusoria is of such importance that we cannot avoid considering them more in detail, and therefore select from the acute G. R. Treviranus the following passage in reference to those cases.
"If we expose spring water to the sun in open, or even in closed but transparent vessels, after a few days bubbles rise from the bottom, or from the sides of the vessel, and a green crust is formed at the same time. Upon observing this crust through a microscope, we discover a mass of green particles, generally of a round or oval form, very minute, and overlaid with a transparent mucous covering, some of them moving freely, whilst others perfectly similar to these remain motionless and attached to the sides of the vessel. This motion is sometimes greater than at others. The animalcules frequently lie as if torpid, but soon recover their former activity.
"As the corpuscles constantly become more numerous, the crust increases likewise. After a few weeks the latter acquires a certain thickness and consistency. If we examine it in this state, it appears exactly as described by Priestley. It looks in fact like a slimy sediment of the water, which has become green under the influence of the sun without presenting any trace of organization. The green particles, which were visible at the time of their formation, are now so crowded together, and perhaps so changed in their organization, that the most attentive observer, unless he had closely followed their metamorphosis step by step, would hardly be able to discover the traces of their primitive form.
"A few weeks later, when the crust has assumed a still greater ​consistency, it appears to have become a confused mass, or an indurated green mucus. When the mass is broken and observed through a good microscope, the original green corpuscles appear again, but changed in form, enveloped in a slimy matter, and interwoven with small transparent threads resembling slender colourless glass tubes, and show irregular yet visible movements. They approach each other, return again to their former position, become entangled with each other, and again disentangle themselves. If observed at the instant when such movements occur with the greatest energy, these little filaments have all the appearance of diminutive eels; in fact they are in some degree similar to the small vermiculations observed in vinegar. We may often discover in them even peristaltic motions. The white colour and the motion of these filaments last but a certain time. After a few weeks more, the crust becomes more solid, uneven, and raised here and there into irregular protuberances. The threads (or filaments) become more distinct; they are green, and scattered about without order, chiefly on the most prominent part of the crust, without however rising over its surface, which remains smooth and rather hard to the touch. The crust itself presents scarcely any traces of the original animalcules.
"If the crust be left undisturbed, and the water be now and then, but seldom, renewed, the unevennesses of the crust increase and rise in a pyramidal form. As soon as the pyramids are formed, the green threads, winding irregularly through the unevennesses of the green crust, rise also, become developed, and dispose themselves along the pyramidal bodies, toward the upper parts of which they become particularly visible; the rest is of a gelatinous substance, of a sufficient consistence to maintain its form as long as it remains under water. If these productions belong to the class of zoophytes, they must be ranked among the Tremellæ."
Some have indeed denied the actual production of organized from unorganized matter, since distilled water over quicksilver does not produce any green matter. But in the first place it is not easy to see why a metamorphosis should not be regarded as such because it occurs only under certain given circumstances; in the second place, it is also very possible that in a process so little favoured even by pure water, the quicksilver, on account of its property of counteracting production (a property which renders it so useful as medicine), may destroy or prevent the infusorial fermentation, as it has been called.
We think therefore that we are not in error when (combining the consideration of these important changes with our general inquiries into unorganized matter,) we recur to the proposition we have before laid down, viz. that the multiplicity of the phænomena of nature rests upon one unity; that nature therefore nowhere presents either an absolute difference (for such changes would then be inexplicable), or an absolute identity; and consequently, if we give the name of ​substance to the real, or that which is the condition of the phænomena of nature, this eternal substance causes by a continual metamorphosis the appearance and disappearance, the perpetual change of natural objects; a real creation and annihilation being as inconceivable as a limit to universal nature.
Of the Organic Kingdom.
The animal stands in the same relation to the vegetable kingdom as organized bodies in general do to the unorganized, that is, as unities unfolding themselves into multiplicity; for as in the activity of individual terrestrial organisms we observe not merely a power peculiar to them as organisms, viz. organic life, but likewise that activity which appertains to them as parts of universal nature, viz. physical life, gravitation, chemical properties, &c.: so also we find in the animal kingdom, besides the life peculiar to animals, the properties peculiar to vegetation. But further, according to our previous inquiries, so little difference can we trace between the unorganized and the organized in their essence and their various relations, that the organized merely presents the unorganized body in higher power, and in closer unity, and in more perfect independence. In like manner the absolute and essential difference between an animal and a plant is so little, that the animal is to be considered only as a plant which has attained a more complete unity, independence, freedom, and power; which will be more satisfactorily proved in the following pages, where we intend to submit the life of plants, as well as that of animals, to a closer examination.
The Vegetable Kingdom.
Speaking of the crystal, we stated that it forms itself by an inward living principle, but that when formed it appears deprived of individual life; whilst organisms, on the contrary, (though to be considered as in a state of continual transformation and growth,) first manifest their real life when they are completely developed: In the same manner we may say of the plant when compared with the animal, that though the plant be in one view formed in order to live, yet even when developed it strives only after a progressive organic formation and real development as the highest aim of its life; whilst, on the other hand, the whole end of the activity of animal life is not mere organic formation, but also free self-determination and ideal development. A proposition which may be also thus briefly expressed: If in universal nature, and in every individual that forms a part of the universe, we must distinguish between the internal unity or law, and external multiplicity or sensible phænomena, we find that in the plant the multiplicity overbalances the unity; in the animal, on the contrary, the unity overbalances the multiplicity. But since a body which possesses less unity is thereby more precisely marked as an integrant part of a superior whole, and, on the contrary, a body possessing greater internal unity appears to be on that ​account more a whole in itself, hence we know why the plant is from necessity more closely connected with the organism of the earth than the animal; considered in which point of view, the principal peculiarities of vegetable organization are capable of a general explanation.
As the first consequence of the above fundamental peculiarity, we have to consider the division of the plant according to the direction of the two principal properties of the terrestrial organism, that is, in its tendency to inward unity (gravitation), and in its relation to the higher natural bodies (light). In this point of view, the plant must be regarded as consisting of two parts, the terrestrial and the aërial, the former consisting of the roots and stem, the latter of the leaves and flowers. From the division, or dualism, thus characterizing the plant, there follows also as a second consequence the want of internal unity in the formation of the plant in its relation to space. Moreover, while we see the animal endowed with different systems of organization, the one for absorption, assimilation, and secretion [Stoffwechsel], the other for sensation and motion, and the first system inclosed within the second in the form of intestines; the plant, on the contrary, wants the intestines properly so called, and possesses nothing to correspond with the absorbing and assimilating intestines of the animal, but that which we call the root; so that while the animal, as a unity in relation to space, exists one half within the other, the plant, on the contrary, as a duality in relation to space, appears one half upon the other. Hence we may moreover infer the original homogeneity of both halves; and this circumstance renders the reversion of their functions possible, so that the branch is converted into a root, and the root into branch, leaves, flowers, &c., as is proved by experiment. A third consequence is, that as the union of two points appears as a line, the line is the archetype of the plant; while, on the contrary, (as we shall show hereafter,) the globular form is the archetype of the animal body. The root, being subject to the law of gravitation, strikes downward toward the centre of the earth; the stem, the leaves, and the flowers, on the contrary, follow the light, and rise in the opposite direction, so that the whole represents a perpendicular line. The experiments instituted by Count Buquoi, in order to ascertain the constancy of these directions under unusual external circumstances, are in this respect well worthy of attention. Seeds were put into a layer of mould lying loose at the top and bottom ; but, though placed closer to the lower surface, instead of growing out of this, they pierced through the far stiffer part of the layer, so as to grow out of its surface. Plants which were set upside down in a flowerpot always bent their flower-stem around the edge of the pot, and grew upwards. A fourth consequence of that fundamental property of the plant is its ​fixing itself upon a given spot; while, on the other hand, locomotion is the characteristic of the animal kingdom. For there is no comparison between plants taking root, and the adhesion of some animals, corals, and oysters, to the ground by means of their shells. In the latter case there is not, as there is in that of the plant, an active dynamical intrusion into the maternal bosom of the earth for the sake of nourishment and life, but a mere mechanical hold of the surface. A fifth consequence is the more marked dependence of vegetable life on the life of the earth. Whether the vegetative organization awakes and develops itself, or sleeps and dies, depends accordingly on the position of the planet with respect to the sun and other heavenly bodies, as well as on the peculiar development of the soil. Though, these circumstances affect animal life also, it is not to be denied that they do so in a far inferior degree, and that the progress of animal organization imparts an independence of which the plant is utterly incapable. As the sixth and last consequence arising from the less perfect unity of the plant, we are to consider not only the dualism already mentioned, but the peculiar nature of every bud; and every internodium may be considered as a whole in itself, or in some measure an individual plant; wherefore a bush or a tree is more properly compared to an aggregate of animals (a coral bank) than to a single animal. In this way we shall easily comprehend the various modes of propagating plants, in which a bud (an eye) and the shoots that issue from it renew the parent organism, and that which we see in the bud is exhibited likewise as tubercles in the root or also (as in the genus Allium) near the flower, or as the bulb, and always possessing the power of reproducing the whole plant out of itself; nay the very seed is but an improved and more perfectly compact picture of the bud.
If we closely examine the structure and composition of plants, we find that, like the organism of the earth itself, they contain solid, fluid, and gaseous elementary particles. We see that in the plant, as well as in the earth, the fluid contributes to the formation of the solid parts, and that the finer and therefore more destructible organization of the plant is composed of chemical elements, namely, the carbonic, hydrogen, and oxygen gases. The transition of the fluids into solids, and consequently the history of the formation of the proper body of the plant itself, is evident in its primary structure, that is, in its cellular tissue. If we call to our recollection the history of the primitive formation of the rudiments of organic bodies in the green matter of Priestley, and see in this the conditions of this formation,—whilst, under the influence of light and gravitation, some particles of the original fluid attain the nature of individual beings, as well as a tendency to internal unity, and consequently a globular form,—it becomes clear that this development cannot occur without a separation of those particles from the rest, without an individual limitation in form of a spherical surface; so that the rudiment of ​animal life appears to be a hollow globular body. Consequently when the effort to attain a higher unity or a more perfect organization presses several of these globuli, possessing solid though weak surfaces, one toward the other, the surfaces, by mutual pressure, are necessarily modified into different geometrical angular bodies. In the most imperfect plants we observe, as a consequence of an imperfectly developed internal structure, that in their single cells, which press each other but slightly, the globular form prevails, although on account of the linear direction peculiar to plants (see p. 235) it is elongated into the'ellipsoid; while in the more perfect plants, on the contrary, the single cells of their tissue appear, in consequence of the mutual pressure, in the form of regular dodecahedrons. Looking upon the cellular formation as the basis of the whole plant, and considering that the plant itself in its primitive destination is dependent on its relation to the planet and its unity (gravitation), we are fully entitled to identify the anatomical system of the cellular tissue, as the proper reproductive system of the plant, with terrestrial gravitation and the planetary body itself, inasmuch as that principle may be considered the basis of the whole organism of the earth. But since, in the organism of the earth, light and air, as constituting a second integrant part, stand opposed to gravitation [der Nachtseite], and since the plant bears a relation not only to gravitation but to light also (see p. 235) when its formation is complete, it will necessarily present a second anatomical system, namely that of the spiral vessels, which have been very justly considered of late as the organs that perform in plants the functions of nerves. The lower plants, which want no light for their development, are not provided with spiral vessels; in the more perfect plants, on the contrary, the spiral vessels are as essential a part of the organization as the cellular tissue. In fine, between both these systems of the cellular tissue and the spiral vessels (the earth and water system, and the light and air system, as they are called by Kieser,) the epidermis stands as a binding and connecting member, whose vessels appear to be the more perfect intercellular ducts, and its pores the orifices of these vessels.
As the anatomical systems of plants are therefore but very few, the multiplicity of their external organs, which unfolds itself in the most beautiful progression and regularity, is so much the more important. Whilst the root, penetrating more deeply in the direction of the earth, spreads itself with uniformity, the plant elevates itself more and more into the light, and attains a more delicate and perfect organization; in which process it is a fact deserving most particular attention, that this perfectibility does not manifest itself in the production of new organs ​entirely different from the former, but in a continually progressive transformation of the original types, a succession of metamorphoses, on the nature of which we have received the most interesting information in he excellent observations of Goethe. It appears that while the first rough type, as it were, of the whole plant is contained in the coatings or leaves of the seed (cotyledons), which abound with a gross and yet unelaborated sap; the same type is manifested more plainly in the successive divisions of the stem (internodia), and in the leaves, in which, when we compare the upper with the lower leaves which surround the stem, its progressive improvement becomes very distinctly evident. As soon as the plant has formed its leaves, which perform the functions of the organs of respiration and secretion, and has thus purified its fluids, it goes on to produce the flower, which is its most complete organ, entirely under the influence of the light. Even this transition is not performed suddenly, but is prepared by the formation of the calyx, wherein the leaves of the stem begin to contract themselves, while they unite in greater numbers around a common axis in the same plane: this formation shows itself most evidently in the collective calyx of flowers belonging to the class Syngenesia, in which the pappus performs the function of the calyx of single flowers. Moreover, the calyx itself constitutes the most evident transition to the corolla, the functions of which it often performs; and the corolla is only a finer calyx for the organs of generation, which, as the most compact and perfect organs, issue forth from their last organ of development and preparation, as from a covering which they have last thrown aside. It is a remarkable fact, and one which places the correctness of these views beyond doubt, that too rich a nourishment, and the accumulation of too many fluids not yet properly purified, may cause a retrograde organization of these parts; the organs of generation may be transformed into flower-leaves (as in double flowers), the leaves of the calyx may be changed back again into leaves of the stem (as is often the case in the calyx of the rose), and instead of the organs of generation, a new shoot or internodium, bearing a new flower, may appear (as in the proliferous roses or Rose-kings). When, after such successive progression, the plant has reached the highest point of polarity between root and flower (gravitation and light), between which the stem and leaves may be considered as mere connecting links, similar in their function to that of the epidermis between the cellular system and the system of the spiral vessels, the same opposition appears once more under the form of male and female stamina; the latter of which, as containing the germ of a new plant (the seed), belong more to the reproductive system, and stand more under the influence of the earth. Wherefore the inferior plants, such as ​mushrooms, ferns, &c., produce their seeds immediately without the aid of the male stamina, and this circumstance accords with their texture, which is merely composed of cellular tissue. On the other hand, the male stamina, containing a generating life-imparting principle, that is, the operation of light, come nearer to animal nature. This view is in perfect accordance with the power of motion which is often to be observed in these parts, as well as with the very probable hypothesis, that the cause of the scent and of the colour of flowers may be traced to the elements of the male pollen, which is contained in their leaves. We have already stated that the seed itself being an indifference emanating from this highest polarity, contains the most concentrated image of the bud. As it has thus within itself in idea the whole organism of the plant, it is capable of reproducing in reality the whole plant out of itself.
Proceeding from this short survey of the principal phænomena of the development of plants to a further examination of their active manifestation of life, we shall find that even in this respect the vegetable kingdom, as a part of universal life, is connected with inorganic nature. It has been already observed that the life of the plant consists chiefly in the formation of its organs; whence it follows, that its most essential and fundamental activity manifests itself in the process of assimilation and secretion, as well as in the circulation of the sap, which is nothing but a repetition of the chemical attraction and repulsion observed in unorganized matter. But since the circulation of the sap is not effected by any independent peculiar organ of circulation, (such, for instance, as a kind of heart,) we must suppose this movement to be, like the ebbing and flowing of the tides, the effect of a certain attraction, partly originating in the structure of the plant, and partly in its external relations; unless we should prefer ascribing it entirely to the motion of fluids in capillary vessels, that is, in other words, to the laws of capillary attraction. But the laws of capillarity have surely but a limited influence in this case: capillarity may indeed enable us to explain the phænomenon of the rising of fluids, but not their progressive motion, and still less the flowing off of the sap when the plant is cut or injured; because a capillary tube never can overflow, and that for the very cause which makes fluids ascend, namely, their adhesion to the inner surface of the vessel. Hence, although capillary attraction has some share in the circulation of the plant, it is evident that this depends upon some higher cause. It has been already shown that the polarity of the plant between root and flower, which depends on the elementary polarity between gravitation and light, is also visible in the relation of the functions of both those parts, the root being particularly adapted to attraction and absorption, but less fit for secretion, and the ​leaves and flowers being particularly capable of secretion and expiration, but less fit for absorption. Polarity is therefore the cause which brings the sap into motion by reciprocal attraction and repulsion from the root to the leaves and flowers, and from the leaves and flowers again to the root: a motion on which, moreover, the physical powers—which, as the condition of both these parts, we have named vegetative poles, namely the powers of light and gravitation—must have a most decided influence; since, for instance, it is a well-known fact, that the perspiration of plants is very different according to the degrees in which they are exposed or withdrawn from the light of the sun. But besides those active properties which contribute to the organic formation of plants, some of them possess a peculiar mobility, which seems to arise from real sensibility, and at the first glance presents a perfect line of demarcation between the vegetable and inorganic bodies. In order to have a clear insight into this fact, it is necessary to fix our idea of the word sensibility, as that which we would be understood to convey most correctly, if we say that it consists in the change operated by outward or inward circumstances in the feelings of a being conscious that it exists as a unity; consequently if we deny sensibility to the stone or the mineral, it is not because such a body is not subject to the most various agitations and changes, but because it is merely a member of a higher unity, and in itself is to be considered as an individual, not as a true unity. In regard to the plant we may say that it has become an organic unity; but on account of the dualism (see p. 235.) prevailing in its totality, and its being therefore bound as it were to the external world, we may with safety deny that it is conscious of its own unity; for in order to have self-consciousness, or an internal perception of unity, there must be, not merely that ideal unity which belongs to organized beings in general, but that real manifestation of unity which arises from the continual action and reaction of all the organs and an organic centre. But such action and reaction are not to be found in the plant, in which each bud may be considered as a whole; so that this real unity, as we shall hereafter see, is possible only in the animal, in which the organs are connected with a unity by means of the vascular and nervous systems. But if we cannot suppose plants to be possessed of sensibility, how can we account for their movements towards the light, the shrinking of the sensitive plant from the touch, the closing of the Dionæa by mechanical irritation, or the inclining of the stamina towards the stigma, and the regular embracing of extraneous bodies, and in definite directions, by the creeping plants, &c.? In our opinion all these phænomena are to be accounted for in the same way as the rotation of the earth, the motion of falling bodies, the oscillation of the sea in its ebbing and flowing, the attraction and repulsion of the cork balls in the electrometer; that is to say, we think that they are entirely the effects of external disposing causes, and therefore the consequence ​of a susceptibility or capacity to be effected by those external causes. This property, so far as it is conducive to the excitement of organic activity, has been named irritability, but always without annexing to the word a sufficiently precise idea. We think it therefore, not superfluous to illustrate it by some examples; when, for instance, a body is to be put in motion by an impulse, it is necessary that it possess mobility, or the capacity to be put in motion. It is the same with chemical operations: in order that a body be acted upon and decomposed by another body, it is requisite that the former be susceptible of this chemical action. The case is the same if an organism as a whole, comprehended in an enduring form, is to be affected by external influences; except that we must here distinguish whether the activity called forth by this influence appears as a change in its physical properties, for instance in its extension; or as a change in its own organic activity, its formation; or in the mutual relation of its single parts. In the former case we name this property a physical receptivity, in the second irritability, and the exciting power a stimulant; from which it is clear that the same influence can act both as a mere physical power and as a stimulant: heat, for instance, can expand a body, and at the same time quicken its organic formation or growth; in the latter case it acts as a stimulant. Hence it follows that the irritability of the plant stands in the same relation to animal sensibility, as its own physical receptivity stands to its irritability. While the plant therefore, from being indebted for its own movements to the influence of external causes, approaches more nearly to universal nature, and is therefore further separated from animal life, to which it approximates again in the inclining of the stamina towards the stigma, this movement, though independent of its own will, originates in an attraction inherent in the plant itself.
Having hitherto been occupied in considering the influence of the organization of the earth upon plants, it necessarily follows that we should consider the influence which the vegetable kingdom exercises upon the life of the earth; for even though we should not be inclined to consider that the origin of the vegetable kingdom in general necessarily marks an important epoch in the formation of the earth,—as for instance, in the development of the plant, the production of a single organ (as the flower) from a particular influence is to the whole plant,—yet the transformation of vast masses of vegetable substances into strata of pit and Bovey coals, into strata of turf and of vegetable mould, and particularly the influence of living vegetation upon the surface of the earth and atmosphere, are objects too striking to pass unnoticed. In the latter point of view it is particularly worthy of remark, that the origin of brooks and streams is owing to the existence of woody mountains, and their greater attraction of atmospheric vapours; wherefore we often see streams dried up, on account of the destruction of the forests in which their sources lay; a ​circumstance to which modern travellers ascribe the present dry desert state of Greece, in which several streams celebrated by the ancients have totally disappeared, leaving behind a dry and barren soil, because the woods which contained their springs were wasted and destroyed through barbarism and neglect. If, lastly, we consider how essential an influence the course and deposition of rivers have upon the surface of the earth; how far all countries have been produced by their rivers (as, for instance, Lower Egypt by the Nile, or the regions of America, towards the lower part of the Mississippi, by the alluviations of this river); we find here again the bond of mutual relation and affinity which connects organized and unorganized terrestrial bodies by means of vegetable life manifested with sufficient distinctness.
The Animal Kingdom.
As the plant may be considered a crystal continually developing itself in a constant change of its matter, in like manner the living animal body so nearly represents a plant which has reached a higher unity and faculty of self-determination, that although the animal still remains a part of a higher unity, and is closely bound to the earth by the necessities of life, yet this hold taken of the animal as compared with that taken of the plant, is even less in degree than that which we observe in the plant as compared with the unorganized body. For this very reason, the animal presents, among natural bodies, the most perfect idea of an organism (see p. 226); and as we can prove mathematically that there are only three fundamental numbers (which are continually repeated in all forms of perception, namely, unity, its division into duality, and the reunion of the unity and duality in trinity), which are exemplified in our conception of space through the threefold dimension of length, breadth, and thickness,—in like manner the threefold succession of inorganic vegetable and animal life exhibits the members which together afford the idea of an organism, viz. multiplicity, development, and unity.
Since the addition of the idea of unity constitutes the perfect idea of an organism, just as thickness, added to length and breadth, constitutes the idea of a body, it is evident that the unity of the animal body presents and affords in reality a perfect idea of an individual organism. We have already observed that the peculiarities of vegetable life may very well be collectively ascribed to its want of inward self-independence; in a similar way we may deduce all the peculiarities of the animal organism already alluded to, from the idea of perfect unity which is characteristic of animal life.
Consequence the first.—If the plant, exposed alike to gravitation and light, is divided into root and stem, into a terrestrial and an atmospheric part, the animal, being more independent, is less bound to the organism of the planet to which it originally belongs, and is consequently more ​under the influence of light; wherefore, though sometimes fettered to the earth, it is by no means fixed or rooted in it, to which circumstance it owes its faculty of locomotion.
A further consequence which flows from the above consideration is, that the animal cannot, like the plant, draw its nourishing juices from the soil, because its whole organism has a tendency to inward unity; its very root-organs are turned inwards and formed into intestines; from which we are able to show most evidently the origin of the excretory canal and of the absorbent and circulating vessels. Let us suppose for instance a plant A, living with the atmospheric part + aboveground, and with its terrestrial part — underground; let us now detach it from the ground so that all the fibres of its root, a b c c, having struck back into the internal parts of the stem and of the leaves, may be reversed inwards; we shall then have the figure B, in which the part subjected to the light perfectly encompasses that subjected to the earth; and a b appears as the alimentary duct; b, as the cavity of the stomach, and c c as the vessels for distributing the sap.
| A. | B. |
| | C. |
Here we observe how very much in this metamorphosis the plant has assumed the type of the animal body, such as we observe it among the lower classes of animals. In this way we may now see why in the Medusa, the Sea-star, the Echinus, and other inferior kinds of animals, the aperture of the mouth is turned downwards, and the alimentary duct upwards; or in this way we may see that the lower classes want the opposite or posterior opening of the excretory ducts (anus), or that (as is likewise particularly evident in the Medusa) the vascular organs branch out immediately from the cavity of the stomach, and that the leaf-formed parts B, α α, furnish an explanation of the appearance of a kind of ​external respiratory organs or gills (nearly as in the Clio and the Cleodora); or lastly, we may see that the germ γ grows opposite to the mouth, at the hinder extremity of the body, as the generator of a new internodium, that is (in the plant) as the producer of a new whole, or the organ of the plant's propagation; and we are thereby enabled to account for the usual place assigned by nature to the organs of generation. In this way we shall always recognise that which has hitherto escaped the attention of the observer, namely, the analogy that exists between the body of the animal and that of the plant as above metamorphosed, as well as the manifest derivation of the former from the latter.
A third consequence of the above is, that the animal being the realization of the abstract idea of unity, in which all parts must relate to a common centre, the sphere must be of necessity the original type of animal organization, the globe being that which tends to its centre with perfectly equal relations (radii). But, so far as the animal is not merely the upper part of the plant become detached, but likewise contains in itself the organs of the root, the globe must be hollow, and contain within itself the intestines, which can be most clearly pointed out in the lower animals. Because, without taking into account that the Infusoria appear merely as so many living hollow globules or cells (see the history of the green matter of Priestley, page 232, &c.), this kind of structure is evident in the bladder-worm (Cysticercus), in which (see fig. C.) the absorbing proboscis b (therefore called the head) is in reality curved inwards into the cavity of the body a, exactly in the manner described in the hypothetical metamorphosis of the plant into an animal. Similar forms are also exhibited by the Echinus tribe, to which we must add, that microscopical observations show most clearly that the whole of the organic mass of higher animals is composed of minute globuli.
The fourth consequence is, that as unity is the characteristic peculiarity of an organism, there must exist, because of the greater multiplicity of its form, a bond which, while it again unites that multitude, exhibits that relationship to a common centre which accords with its organization. However, since the animal presents two sides, a higher one, turned toward the outer world, and peculiarly animal, and a lower one, turned into itself, destined for reproduction, and so far purely vegetative, the above bond must likewise of necessity be twofold, and bear a particular relation to each side.
Fifth consequence.—No reciprocal action can take place between two bodies, except in two directions, (just as the organism itself appears essentially as body and life under two forms only), namely, in its tendency to produce a change and combination of particles, or to a reciprocal transmission of power. Inasmuch as in the animal the change ​of particles belongs properly to its internal vegetative side, its external side (for the very reason that it is turned immediately to the outer world) will appear as a perceptive and reciprocating activity. But since we may constantly recognise in every mutual relation of body as well as of action a threefold momentum, viz. action, reaction, and connexion or the indifference of both, these three elements must therefore be found also in each of the two sides of the animal organism. In fact we find them in the external (animal) side, as perception, motion, and the connexion of both through the nerves; in the internal vegetative side, as assimilation, secretion, and the connexion of both by circulation. But whatever is true of the bond which in these two spheres gives every form its centricity, the same must naturally be found in the so-called connecting nervous and vascular systems. Yet these two systems must not perhaps be considered as occasioning a real dualism in the organization, but as equally subordinate and reduced to a unity, namely the nervous system, as being the higher, because it belongs to the animal which includes the vegetative sphere.
Sixth consequence. As the plant is not merely occupied with its own change of particles and continual transformation, but when it has attained its perfect development produces the seed, as the representative of all its properties, the true reproduction of the species, we find in the animal likewise a similar reproduction of the species, in so far as even the animal is but a more perfect vegetable nature. The system thus established in respect to the animal, viz. the sexual system, possesses in its nature a polarity similar to that of the plant; for we find in the more perfectly organized animals, a female reproductive and a male impregnating organ. But, on the contrary, we find the lower animals, like the inferior plants (see p. 239), endowed with female organs only. The activity of this system, manifesting itself especially in assimilation, secretion, and (as the basis of these two momenta) in vascular action, belongs to the sphere of vegetation; and there is nothing to be compared with it in the animal sphere, except that activity by virtue of which, in the most perfect animal organism, that is the human, the idea of nature is reproduced by means of spiritual power, and truly developed through science and art.
We have now further to consider the composition and internal formation of the animal body, as well as the nature and direction of its active faculties of life. In the first point of view, we observe that it contains, like the organism of the earth and of the plant, a combination of solids, fluids, vapours, and gases, among which the fluids are again the sources of the rest. Its ultimate elements are principally hydrogen, oxygen, and ​carbonic acid gas, with the additional one of nitrogen, which peculiarly belongs to this kingdom, and the volatile nature of which perfectly agrees with the rapid merging of animal bodies in the universal life of nature, as soon as their individual life is extinct; to which passage, however, the earthy parts, such as bones and shells, offer somewhat longer resistance. In regard to the internal formation of the solid parts of the animal body, it has been already remarked (see p. 244) that the spherical type, in so far as it is peculiar to animal forms in general, is also visible in the basis of all animal matter, so that the molecular substance is the basis of the collective animal body. If we now reflect likewise how in the Infusoria and Priestley's matter, the rudiments of the animal kingdom appear as so many animated globuli, we shall thence perceive that the largest animal bodies themselves must be viewed as an innumerable aggregate of Infusoria, but at the same time united into a living whole. It is moreover worthy of remark, that very essential differences present themselves in respect to the primary formation of the animal body in its different systems. It is also a remarkable fact, that in the organs exclusively proper to the animal,—for instance, in those of sense, motion, and the nerves,—this molecular mass is clearly discernible, partly as the marrow of the nerves (a peculiar grey substance), partly as developed nervous and muscular fibres; while in the organs which are more immediately borrowed from the plant (the vascular system, the skin, and the intestines), we remark again a very decided tendency to cellular formation.
We have now before us two modes of perceiving in its true nature the further formation of the primary animal mass into the single organs of the animal body; either that of attentively watching the development of one complete animal organism in its different stages, or that of observing the succession of the species according to the order of animals in the development of their animalism. Of these two we shall give only the principal outlines of the first series of formation, in which we shall find a great analogy to the development of the plant, but more especially a manifold confirmation of that which we have advanced in regard to the metamorphosis, or rather elevation, of vegetable into animal life. But in tracing the development of the individual animal body through its several stages, we shall take as the main object of our observations the human organization as the most perfect; and thus we shall have occasion to recur to that of other animals in those cases only in which the observations made on the human being itself are deficient in regard to its first rudiments.
​One thing, however, we know with certainty, namely, that the human body, like that of other animals, has its origin in the egg. But the egg itself must be considered as the original animal, as the infusorial creature, appearing in the globular or primary form of animal life, and, like the seed of the plant, containing ideally within itself the whole animal, which, under given external circumstances, it develops really out of itself. Recent observations have shown that the first rudiment of the embryo is formed on the inner surface of the hollow globe of the egg, by folding or turning inwardly a part of the integuments of the egg; which reminds us distinctly of the purely vegetative bladder-worm (Cysticercus, see p. 244), in which the so-called head, or the absorbing orifice, is turned inwards. It is plain therefore that we must consider the egg in this first period of development also as a plant with a root turned inwards (see p. 243); and we find this moreover confirmed by the functionary attributes of its parts, since the first introversion of the integument forms the cavity of the stomach and the intestines, as the first rudiment of the embryo. On the other hand, the external covering of the egg being somewhat similar to the green (breathing) surface of the plant, performs the breathing function of the embryo, and contains also (as the latest observations of Pander have shown), in the external envelop of the cuticle, the origin of the organs of sensation. In a further stage of development we see the activity of formation concentrating itself more in the point turned upwards, and thus producing new opposites. The rudiment of the embryo repeats the above-described form, and the higher animal organs, which commence with the spinal marrow and the vertebral column, originate above the germ of the intestines of the cavity of the stomach. It is now in particular plainly seen how the animal is as it were transformed from a plant into an animal in the manner above described (p. 234). For at the very first the intestines are only attached to the fœtus, that is, the gut lies as yet in the umbilical cord, just as at first the root is attached to and not in the plant; but the intestines are soon afterwards drawn more and more inwards, and by degrees are completely enveloped by the animal organs, which grow simultaneously forwards on both sides out of the vertebral column; and here for the first time the fœtus presents the appearance of an independent animal organism. The vascular system, however, is much more slow in connecting itself perfectly with the fœtus; since it is rather a general connecting medium in the vegetative sphere, and therefore performs the function of a bond of union between the integument of the egg and the fœtus so long as it remains inclosed in the egg. Even at this period of development the relation of the parts of the egg reminds us of the plant; as the fœtus, by means of the umbilical cord, is united to the placenta and integuments of the egg, hold in organic connexion with the maternal organism, just as the flower (which it resembles in respect to the ​development of the organs of generation,) is united by means of the stem to the root, which is held in connexion with the organism of the earth. It is also remarkable, that in the fœtus the direction of the development from the insertion of the umbilical cord is upwards, as we see in the plant that the flower is directed upwards from the insertion of the stalk. For instance, the anthers are never turned back toward the stem and the fruit-germ, or directed downwards, but on the contrary are invariably and wholly directed upwards, unless the flower-stalk and fruit-germ are turned downwards, in which case they also are directed downwards with them. This explains the development of the vertebral column into the head, in which the flower of the collected animal organization appears as completely as the flower of the egg does in the entire fœtus. This fact is still more clearly observable in the central structure of the vertebral column, viz. the spinal marrow, the fibres of which we see more perfectly developing themselves as they ascend upwards, till they terminate in the perfect and noble formation of the brain.
This direction of development in the fœtus, the truth of which is most clearly established by many physiological as well as pathological observations, is also indicated by the position of the entire fœtus, in which we find the head usually turned downwards, but the lower extremity turned toward the insertion of the umbilical cord; in the same manner as the flower of the plant, and the head of the more perfect animal, rise upwards from the ground. Moreover, that the greater weight of the head which occasions it to sink downwards in the uterus is not the only use of that position of the foetus, is evident from the parturition of the quadruped mammalia, since although their standing on four feet must prevent the operation of such a cause, they nevertheless bring forth their young with the head (nay even with the face) forwards.
We can here give but general outlines of the further development of the different systems and organs formed in the fœtus; and with respect to the systems belonging to the animal side of the animal body, and which corresponds to the light side of the plant, we observe that from their constituting the parts originally turned toward the outer world, they are endowed with a tendency to develop their structure in a direction radiating outwards from an internal centre; for which reason we see the nervous system form itself as the radii of a central mass (the brain and the spinal marrow), which develops itself with a perfection continually increasing in proportion as the radiation outwards increases; we see also the ends of the nerves forming themselves either into the organs of sensation, or, as being destined to re-act upon external objects, inserting themselves into the molecular mass of the animal; so that these molecules, disposed into muscular fibres, are drawn, sometimes more and sometimes less ​strongly, towards that insertion of the nerves, according as the action of the nerves is increased or diminished by its centricity; and it is thus that they determine the muscular contraction, and all animal motion. The following figure will explain the contraction and relaxation of the muscle: a b represents the relaxed muscle, and c the nerve in its usual state; d e the contracted muscle, and c$^2$ the nerve in increased action. In the second figure, the contraction of the muscle by means of a diminution of volume is explained by the closer approximation of the points to the centre.
But besides this twofold termination, the nervous system finally branches out also into the vegetative sphere of the body, thus partly determining both sensation and motion, and partly constituting the bond of unity between the different organs of the vegetative system. In the latter point of view the very form of the nervous fibres is remarkable, since they all have an evident tendency to inclose the intestines and vessels in a kind of network. In the same point of view it becomes clear also that, as the inclosing of the lower system in the higher one is characteristic of animal organization, and the rudiments of the nerves always show this peripherous type, the higher animals, and man in particular,—in whom the spinal nerves encompass the common cavity of the trunk, somewhat similarly to the bending of the ribs,—possess a system of nerves appropriated to the vegetative structure, and perfectly analogous to the nervous system of the inferior animals, namely, the ganglionic system, or that of the great sympathetic nerve.
The osseous system is developed uniformly with that of the nerves, and issues out of the vertebral column, as the nervous system does out of the spinal marrow; whilst the vertebral column forms at first but an isolating sheath around the latter, as an earthly substance most powerfully attracted by the nervous system, acting like the sun, and for the most part antagonistically upon the other parts of the body. In a somewhat similar manner, among falling bodies of different specific gravities, the heaviest will always lie undermost and nearest to the attracting centre of the earth. Where the osseous system has acquired its most perfect structure (in the skull) it presents also the original type, the spherical form; on the contrary, like the radii of the nervous system, it branches out more and more in the extremities, a fact which is clearly seen in the increasing number of the bones in each member, from their root in the trunk to the ramification in the fingers and toes.
​In examining the origin of the individual members of the vegetative sphere, of which we have already observed that the formation from without toward the internal parts, namely from the umbilical cord into the cavity of the stomach, presents the organs of digestion (as the internal nourishing root of the animal) and the bowels,—we find that in the progress of organization new organs are formed for the functions of respiration and secretion, to correspond to those of nutrition and absorption. The function of respiration indicates the connexion of the individual organism with the atmosphere, as on the other hand the absorption of grosser matter indicates its connexion with the earth by the root.
As long as the fœtus is inclosed in the placenta it can have no immediate connexion with the terrestrial organism, but maintains rather a reciprocal action with the maternal organism, as is seen in its manner of breathing, which is originally performed through the integuments of the egg (see p. 247). But since it is necessary that an independent organ of respiration be prepared for the time when the fœtus leaves the maternal body and the integuments die away, we find the external surface of the fœtus itself (the skin) developed with its continuation (the internal organs of respiration). The vascular system (hitherto the connecting medium between the fœtus and the integuments of the egg, see p. 247), then becomes the connecting medium between the organs of digestion, respiration, and secretion. The organs of secretion, however, may in a certain respect be considered as a repetition of the organs of respiration, since the evaporation and secretion of gases form a prominent part in the process of respiration. The plant develops, besides the organs of general assimilation and secretion, those of generation: a similar development takes place in the animal also, and precisely at the point where the germ of the fruit is developed in the plant, at a point which is therefore analogous to the insertion of the stamen in the flower; in other words, at the insertion of the umbilical cord into the abdominal cavity, which in the first stage of formation, where we observe the embryo with its pointed lower extremity attached to the inner surface of the egg, is the basin that incloses the genitalia as the calyx does the fruit-germ.
After having considered the transition of the form of the plant into that of the animal, it remains for us now to examine the peculiarity of the active living principle of the animal, in order to ascertain how far this is derived from the active living principle of the plant. But we must first carefully observe, that if we were right in considering (page 239) the chief end of the active living principle of the plant to be its formation, the first active living principle in the animal likewise must be a tendency to acquire individual existence. The whole animal body, as far as regards nutrition, growth, secretion, and its being engaged ​in a continual change of matter in the parts already formed (the vegetative as well as the higher and properly animal parts), lives absolutely the life of the plant. We likewise observe, that here also the fluid parts are the sources from which the several solid parts are formed by different attractive affinities, for this reason, that the external nourishing substances first enter into the fluids, but at the same time the secretions which are given off from the fluid parts of the body are carried away in the form of liquids, vapours, or gases. However, to perform this attraction and repulsion, one condition is requisite which is equally necessary in the life of plants, and that is the circulation of the fluids. This circulation we have seen performed in the plant through the polarity between the root and the flower, and therefore in a linear direction from one end to the other. But since the animal is a plant the root of which is turned inwards, a similar motion of the fluids, from the absorbing to the exhaling pole, instead of being directed linearly from one extremity of the body to the other, must take a centrifugal and centripetal direction, inasmuch as it is but an action and reaction between external and internal organs. We have observed that the circulation of the fluids in the embryo is between the embryo as a centre and the integuments of the egg as the periphery; and that the circulation is not confined to the embryo itself until it has attained its full maturity, at which period it is observed alternating between the heart (as the centre of vegetation) and the periphery; and in the higher animals and man, partly toward the whole bodily structure and its common integument the epidermis, partly toward the epidermis turned inwards in the organ of respiration, and vice versâ. Hence it follows that this movement of the sap or blood is not properly a circular motion, and has therefore no true resemblance to the rotatory motion of the heavenly bodies; because these have an intermediate movement which is the result of attraction and repulsion; whereas the movement of the blood appears as an alternation of attraction and repulsion, which is most analogous to the ascending and descending movement of the sap in the plant. This also leads to the conclusion that both this movement and its direction are originally the mere effect of the polar attraction and repulsion of the fluid itself. Wherefore this circulation may take place without needing any other mechanical aid, as for instance the pressure of the vascular surfaces, of which aid many animals are for the most part destitute. Indeed, the original unimportance of such aids is rendered fully evident by the fact that the vessels, like all other solid parts, are formed only by the circulating fluids,—consequently, that ​the fluids exist before the vessels, and that the direction of the vessels is the necessary consequence of the direction of the fluids.
Whilst through these general considerations we see how the movements of the original fluids maintain reproduction in all parts of the body, a due attention to the different polar directions of vascular activity, according to the different natures of the several parts of the body, will enable us also to perceive their differences of assimilation as well as secretion, and the laws to which they are subject; but these inquiries we cannot here pursue further. We now turn our attention to animal sensation, in order to observe the difference between it and the receptivity of the plant. The animal, containing within itself the organism of the plant, its organic functions must, like those of the plant, be liable to be modified by external influences. This property in the plant we have termed irritability, because irritation immediately causes and calls forth re-action. In the animal, however, the nervous life (as the expression and type of unity, which embraces all the parts of the organism and forms them into a whole.) stands between irritation and re-action; and as each local irritation is communicated through the nervous life to the whole organic unity, to the consciousness of the animal, the perception of the irritation rises to a sensation, and thus it depends more on the free will of the animal whether or not irritation be followed by re-action. The more intense this consciousness is, (it being the unity out of which the multiplicity of organic phænomena is developed,) the purer and more varied must the sensation be, (because a more marked individuality necessarily causes a more varied relationship with external objects,) and the more free the action toward the external world; i. e. the less it will depend on external influence, and the more it will be determined from within. We find therefore that the lower animals, and indeed even the parts of the human body which are less closely connected with the system of nerves proceeding from the brain and spine, exhibit in a greater degree the irritability of the plant; while, on the contrary, the higher nervous life of the human organism presents the flower (or perfection) of individual activity in psychical life, in self-consciousness, the manifestation of which has often been separated from the other branches of organic activity, no less erroneously than its essence (according to the notion of the materialists) has been considered as the sum or result of a certain corporeal mechanism.
We have already observed in our introductory remarks on the idea of life, that the inward unity, or the highest idea of an individual organism, is by no means the effect or the result, but the ground and cause, of external multiplicity, and this is also the case with the ​psychical life— (wherefore the doctrine of Stahl, that the soul forms its own body, if properly understood, is very admissible,—and we hope soon to have the opportunity more fully to develop these views, for which we have not space here, and to confirm the above propositions by more convincing proofs. For the present we have only to observe in general, having already spoken of the manner in which animal re-action depends on muscular motion (see p. 237), how far the more precise independence and the more certain self-consciousness of the animal give rise to the individual forms of sensation.
In the plant, in which irritation causes re-action at the point where it acts, and the single parts of which are independent, but not the whole, irritability (belonging to all the parts) must be general; and this general irritability (raised into a sensation only through the relation of each irritating action to the whole,) is possessed by the animal in common with the plant, and it is therefore included in the comprehensive term feeling. But since in the animal the sensation of each individual part is related to the whole, this sensation can be concentrated and particularly developed, on certain individual points, without injury, or rather with advantage to the whole; wherefore we see that the different sides of perception turned toward the outer world, correspond in number with the different organic systems turned toward the outer world, and with the qualitative influences of various kinds acting upon the organism; so that if mere Feeling gives us only a knowledge of the state of our own organism, the individual senses of hearing, seeing, smelling, tasting, touching, &c. afford us a clearer consciousness of the external world, through a local alteration of our own condition.
If in closing these observations, intended to show the progressive development of animal life out of the life of the lower kingdoms of nature, we look to the changes which animal life operates upon them, facts present themselves worthy of the most serious consideration. We have seen how the vegetative life is nourished by inorganic life, and how vegetation in its turn operates changes in many ways upon the surface of the earth, and even on the atmosphere. So again we find that the animal kingdom maintains the most active relation with the vegetable life and with the elements of the earth and of the air. We see coral rocks and islands raised from the bottom of the sea by animated beings apparently insignificant, which, existing before the creation of Adam, now elevate their lofty tops as mountains of the continent; we see the animal kingdom penetrating into parts of the earth seemingly impenetrable to all living creatures; moreover, we observe that here also, where, according to the eternal laws of nature, the highest is ​connected with the lowest, and the human organization itself falls at last into inorganic dust, the form and culture of the land, the course of the rivers, vegetation, and population, along with different animal species, are in various ways changed by the activity of man. If therefore we compare the condition of countries which have once flourished and exhibited the activity of human industry, with the desert state which they now present, when, after the fall of these nations, they are deprived of the care and culture of man, we shall be convinced that, as a modern writer expresses himself on this subject, "Not only does man need the earth in order to live and be active, but the earth also stands in need of man."
We may hope now to have attained the object of the present essay, if, by throwing some new light upon certain aspects of infinite nature which have hitherto remained less observed, we have awakened a new attention to the indissoluble union as well as the beauty and regularity of the phænomena surrounding man and existing within him; and as the contemplation of these must necessarily stimulate us, not only to penetrate more deeply into the mysteries of science, but also to conform our own inward life to that harmony and purity which are presented by universal nature; for what would be the value of all scientific knowledge, did it not manifest itself in ennobling and elevating the human mind?
* ↑ [An investigation of this part of the subject will be found in a paper "On the Origin and Production of Matter, and on its alleged Infinite Divisibility," in the Philosophical Magazine, First Series, vol. lxii. p. 360, et seq. See also vol. lxiii. p. 372.—Edit.]
* ↑ See the experiments of J. F. W. Otto's System in an Universal Hydrography of the Earth. Beriin, 1800.
* ↑ See Kant's Physic. Geograph., edited by Rink, Pt. I. p. 61.
* ↑ See Otto's Universal Hydrography, p. 520—550.
* ↑ On the formation of the water-drop, see p. 229.
* ↑ See Beitrage zur Naturgeschichte der Erde: pp. 58 and 69. Freyberg, 1801.
* ↑ Biologie, vol. ii. p. 302.
* ↑ Similar results are obtained from distilled water, though far more rapidly when mixed with organic substances.
* ↑ Skizzen zu einem Gesetzbuche der Natur. Leipzig, 1817, p. 315.
* ↑ Kieser's Grundzüge der Anatomie der Planzen. Jena, 1815, p. 9.
* ↑ Ibid., pp. 16–19.
* ↑ Ibid., pp. 16—19.
* ↑ Ibid., p. 19.
* ↑ Versuch die Metamorphose der Planzen zu erklären. Gotha, 1790. Reprinted in the Hefte zur Naturwissenschaft und Morphologie, 1817, i.
* ↑ [Rosenkönigen, Germ.]
* ↑ Goethe's Morphologie, p. 23.
* ↑ Carus, Lehrbuch der Zootomie, p. 327.
* ↑ Ibid., p. 578.
* ↑ Carus, Lehrbuch der Zootomie, p. 482.
* ↑ It is only in this way that the origin of the sensible side is capable of a scientific construction.
* ↑ The observation of the development of organization in the series of animals, is the idea upon which Carus's Manual of Zootomy is founded, to which he here refers his readers.
* ↑ The essential difference between the earliest and the later form of the circulation in the egg during the process of incubation has been recently demonstrated in the beautiful experiments of Pander.
* ↑ [Rather,—as the sum or result of the powers and properties, physical, vital and sentient, with which the Creator has endowed the human frame.—Edit.]
* ↑ [psychischen Leben, Germ.]
* ↑ See on this subject the observations which G. R. Treviranus (Biologie, vol. ii. p. 7) has collected from the instructive reports of other naturalists.
* ↑ I. F. Koreff, De Regionibus Italiæ aere pernicioso contaminatis Observationes. Berol. 1817. 4.
NOTE.
[In some of his reasonings the Author will, perhaps, be thought to deal with abstract terms as if they were real essences, or to employ them in a sense somewhat peculiar. Whatever difference of opinion may, however, exist with regard to the speculative parts of this memoir, it will, it is presumed, be acceptable and interesting to many readers, as showing the manner in which physiological subjects are viewed by some distinguished writers on the Continent.—Edit.]