§ II.—CHAPTER VIII.

TYPICAL FORMS DIVINE WISDOM.

THE general conception of order with which we set out, has in the few last chapters become mixed up with the more special conception of design. The teleological aspect of organic phenomena is that which most readily fixes the attention of the Natural Theologian, as it is that which has hitherto proved the most successful key of discovery in prosecuting their study. Under the influence of the illustrious Cuvier, this teleological view had assumed such a prominence in physiology as almost to obscure the more general view of a unity of plan or order. Of late, however, and especially through the profound and laborious researches of Professor Owen, this latter view has begun to claim renewed interest. In his two works—“On the Archetype and Homologies of the Vertebrate Skeleton,” and “On the Nature of Limbs”—he has especially shown its value and fruitfulness as a guiding principle of investigation in comparative anatomy; and the same principle has, in truth, been gaining ground in the whole region of physiology, as probably 172 furnishing, here no less than in other departments, the deepest and most pervading key of explanation. It is felt now, at length, after the extravagance of polemic on either side has passed away, that there is no necessary contradiction between the more special and the more comprehensive and yet grander doctrine.

We have already seen the numerical relation which subsists between the different parts of plants. In the great division of the vegetable kingdom, 3 is found to be the pervading or typical number of the monocotyledonous plants, and 5 the pervading or typical number of the dicotyledonous. This numerical unity is found, on closer examination, to be merely a single indication of the typical unity which, throughout the whole range of the vegetable kingdom, underlies its infinite variety. Beneath all this variety, apparently and in reality so boundless, there emerges to the critical gaze an identity of form of the most interesting and wonderful character.

The science which treats of this pervading feature of the organic kingdom has been termed Morphology,⁹⁸⁹⁸   In so far as we know the term, morphology was first made use of in application to anatomy in the year 1819, by Burduch, in his treatise Über die Aufgabe der Morphologie. Leipzig: 1819. and has within the last half-century drawn the special attention of naturalists. In so far as it relates to botany, Professor Schleiden has devoted one of the chapters of his very attractive work, The Plant, a Biography, to the subject. He thus describes the importance of form to the plant, and the frequent subordination of every other thing to it:—

“Whether it arises from the essential nature of the circumstances or not, we cannot say, but, at least so far as appearance goes, the production of shape is so prominent a point in the natural history of plants, that all the rest has often been forgotten for its sake; and thus the study of form, or morphology, becomes in any case the most important branch of teaching in all botany. But it would be a great mistake to suppose that morphology is merely a meagre enunciation and description of forms. It is also a scientific question; it has to seek for the knowledge of laws, and must, at least as a preliminary step, arrange the multitude of appearances under primary points of view, place them according to rule and exception, and so gradually approach nearer to the discovery of the actual laws of nature.”⁹⁹⁹⁹   Pp. 81, 82.

The fundamental idea of morphology, therefore, is the recognition of a common type of construction among plants and animals. In the case of the former, with which we are immediately concerned, science, penetrating beneath the mere diversity of organs, and their enumeration and classification, discerns a persistent unity of plan or law, upon which the whole plant, in its various and complicated structure, is moulded. And it is remarkable that this beautiful conception, to which science owes so much, was, in the first instance, due to the vivid intuition of a poetic, rather than the patient induction of a merely scientific mind. It was to the fine and subtle glance of Goethe, roaming through nature 174with so rich a perception of its harmonies, that typical forms of structure, in the vegetable world, first revealed themselves. His Versuch die Metamorphose der Pflanzen zu erklären, in 1790, contained the first formal exposition of the doctrine of typical unity, and must, therefore, be considered to have laid the basis of scientific botany. It was not, however, till thirty years later, when the speculations of Goethe were taken up by de Candolle, and embodied in his work on Organography, that they attracted general attention, and passed into the scientific mind of Europe. The idea of the poet only then became the recognised doctrine of science.

Goethe, drawn to nature from the promptings of its mirrored harmony within him, carried over, as might be supposed, a somewhat too ideal view of unity to the plant. His idea of a typical plant, “whereby he signified an ideal plant, the realisation of which, as it were, nature had proposed to herself, and which she had only attained in a certain degree in the individual plants,” is considered by Schleiden to be deficient in clearness and grasp of reality. And it would indeed have been wonderful if the first fresh glance of the poet had expressed with perfect precision the deep-seated truth of nature. It cannot even now be said that the fundamental forms of vegetable structure have been precisely determined; some, with Schleiden himself, finding a radical twofoldness, and others aiming to establish a unity¹⁰⁰¹⁰⁰   See a paper on “Typical Forms” in the North British Review, August 1851, in which an attempt is made “to reduce a plant, by a more enlarged conception of its nature, to a unity.” The paper, understood to be from the pen of Professor M‘Cosh of Belfast, gives throughout a very informing and suggestive view of the whole subject; and we have been greatly indebted to it in the composition of this chapter. as 175 the most general plan of the plant. It is only by very patient and comprehensive processes of induction that the most hidden order of organic nature can ever be discovered. As Schleiden says, “glorious systems may, indeed, be thought out on paper in the study, but these have no meaning or importance in the actual world. Thus, as we enter upon these things, we must rather modestly inquire whether nature is inclined to display her mysteries to us,—whether she will, in this or that individual instance, make manifest what characters are essential in their shape; in a word, what basis she will afford us for the erection of our system.”

It will suffice for our general purpose to present a very brief sketch of the now established reduction of the plant to a twofold type of structure, as exhibited by Schleiden. The two representative organs, to which all the others can be reduced, are the stem and the leaf. The root, and the trunk With its lateral branches, and these again with their lateral branchlets, are simple modifications of the former. All these are of “the same structure, and tend to assume the same form.”¹⁰¹¹⁰¹   North British Review, August 1851, p. 396. “If a thousand branches from the same tree are compared together,” says Lindley, “they will be found to be formed upon the same uniform plan, and to accord in every essential particular. Each branch is also, under favourable circumstances, capable of itself becoming a separate individual, as is found by cuttings, buddings, grafting, and other horticultural processes.” Each branch or branchlet, therefore, is simply the plant repeating itself, in diversified 176outline, as it advances in growth—each containing within itself the germ of individual existence, and ready to become an individual plant on the application of the proper means. The term phyton has accordingly been given with propriety to each single part.

Upon the stem, and out of it, grows the leaf, which, in its turn, is the undoubted type of all the special organs of inflorescence, the calyx, corolla, stamens, and pistils. The sepals of the calyx, and the petals of the corolla, or flower commonly so called, are obviously enough foliar in their structure. But the stamens and pistils have been proved to be no less so, little as, on a mere cursory inspection of them, this might seem to be the case.

The plant, in its most complete development, is therefore capable of analysis into two distinct parts—a twofold system of constructive order. The diversity of stem and flower is seen to flow from a typical unity in each case; and some have carried back, as we have said, the whole diversity to a radical unity in the stem. If we cannot contemplate the special relations and uses of different organs of the plant without recognising in them the clear marks of design, it is no less impossible, surely, to contemplate this wonderful unity of organisation—this plan of structure, underlying the whole vegetable creation—without the conception of Mind forcing itself irrepressibly upon us.

But this conclusion is still more strongly enforced by the most general glance at the result of Professor Owen’s researches in comparative anatomy. The labours of this great investigator have opened up a new field of interest 177 and significance in anatomical science. Carrying along with him the principles and conclusions of Cuvier, he soon found that their very force impelled him forward to a more profound and comprehensive principle of discovery, which, while it had been perverted by the arbitrariness of previous theorisers, is yet of incalculable value and importance. The simple fact of corresponding bones in different species, freely recognised by former anatomists, became significant to him of a great doctrine of homology, running through the whole of the vertebrate skeleton. By the term homology he expresses the unity or identity of character between the bones so answering to one another in different animals. The bones themselves he calls “homologues,” in contradistinction to “analogues,” which he applies to parts performing the same function; whereas homologous parts, identical in character, may exhibit every variety of form and function—are the same organs, in fact, under whatever change of circumstances. Thus the fore limbs of a quadruped, the wings of a bird, the pectoral fins of a fish, and the arms of man, are respectively homologous, because they are really the same organs, only differently modified; while again the wings of Draco volans are merely analogous to the wings of a bird;¹⁰²¹⁰²   Quarterly Review, June 1853, p. 72. each organ performing the same function, but being wholly different in structure.

Throughout the vertebrate skeleton—from that of the fish, the reptile, and bird, to that of the mammal—from the cetaceans up to man Professor Owen has demonstrated that there are no fewer than seventy of such homologous bones, 178 which may be clearly traced, showing the uniform plan, or archetypal model, upon which the whole vertebrate races have been formed. This vertebrate archetype has been figured by him; and, in connection with the respective type-skeletons of the fish, the reptile, the bird, and the beast, is said to constitute a perfect anatomical study. With the details of the subject we feel ourselves incompetent to meddle; but the great conclusion is one which claims our earnest attention—the fact, namely, of the demonstrated unity of constructive plan underlying all the singular diversity of the vertebrate form. What a pregnant fact is this! and how vast a scheme of order does it open up in the animal creation! “If there be,” says Professor Sedgwick, “an archetype in the vertebrate division of animated nature, we may well ask whether there may not be a more general archetype that runs through the whole kingdom of the living world. In a certain sense there is. All animals, if we except the Radiata, which come close to a vegetable type, are bilateral and symmetrical,¹⁰³¹⁰³   This statement regarding equilateral symmetry must be received with some limitations. have double organs of sense, and have a nervous and vascular system, with many parts in very near homology, even when we put side by side, for comparison, the animal forms taken from the opposite extreme of nature’s scale. And even in the Radiata, where we, at first sight, seem to lose all traces of the vertebrate type, on a better examination many of the genera are proved still to be bilateral and symmetrical.”

There is in this grand conception of typical order a 179 significance for our subject in some respects quite peculiar. Even if it were the case, therefore, that the teleological principle of Cuvier suffered any abatement of its lustre (which, according to a just view, it is yet far from doing) from the promulgation of this more comprehensive principle, the theistic argument would still be far from sustaining any loss. It gains, on the contrary, more than by any possibility it could lose. As if the homage which science had already from all quarters rendered to it were not enough, this latest advance of physiology has returned laden with an offering of most precious and conclusive meaning.

The essential question of Theism, we formerly saw, resolved itself into one regarding the rightful relation of man’s reason to the world at large. Is this reason entitled to bring the manifold life of nature within its own forms, to embrace the cosmical vastness in its own mirror? We found that, in the nature of the case, it is and must be so entitled, as the very condition of science or of truth at all. Reason is not merely a growth of nature, but truly an emanation from the Divine Source of nature, and therefore validly brings all nature within its laws. Now, looking at these latest discoveries of physiological science, are they not found to bear an emphatic testimony to this fundamental position? For what is the typical order recognised as pervading creation but the signal expression of a reason allied to man’s, and yet above it? What is the evidence of an ideal archetype for the world, or any part of it, but the special evidence of a Mind subsisting apart from the world, and antecedent to 180it? For it is clear that such an archetype could never have existed—such a pattern could never have been stamped on creation so deeply inlaid that we are only now discovering it—without a Mind to conceive and plan it. In the language of Professor Owen—language of the highest interest for our subject—“The recognition of an ideal exemplar for the vertebrated animals, proves that the knowledge of such a being as man must have existed before man appeared. For the Divine Mind which planned the archetype also foreknew all its modifications. The archetypal idea was manifested in the flesh, under divers modifications, upon this planet, long prior to the existence of those animal species that actually exemplify it. To what natural or secondary causes the orderly succession and progression of such organic phenomena may have been committed, we are as yet ignorant. But if, without derogation to the Divine Power, we may conceive the existence of such ministers, and personify them by the term Nature, we learn, from the past history of our globe, that she has advanced with slow and stately steps, guided by the archetypal light amidst the wreck of worlds,—from the first embodiment of the vertebrate idea, under its old ichthyic vestment, until it became arranged in the glorious garb of the human form.”

And here appropriately our evidence for the special fact of the Divine wisdom may be said to culminate. Speaking to us everywhere in the laws of nature—in the special ends of organic functions—it seems in these last chapters to rise before us with a clear and vivid force of the most irresistible 181 kind. In all the intricate diversity, and yet vast archetypal unity of organic life, we seem to see with a brightness, undimmed by intervening medium, the impress of a Wisdom as grand in simplicity as it is boundless in fertility.¹⁰⁴¹⁰⁴   The evidence which this archetypal order or unity of plan in creation furnishes of the unity of the Divine Being, is, moreover, deserving of notice. Here, too, the language of Professor Owen is expressive of that sound Christian philosophy, which in him, as in so many of the highest minds of our country, is found in beautiful unison with the most eminent scientific attainments. “The evidence,” he says, “of unity of plan in the structure of animals, testifies to the oneness of their Creator, as the modifications of the plan for different modes of life illustrate the beneficence of the Designer.”