The Leaf
H. Macmillan, LL. D. Genesis 2:5 And every plant of the field before it was in the earth, and every herb of the field before it grew… One of the most beautiful scientific generalizations was the result, not of the patient, persevering researches of the naturalist, but of the dreamy reverie of a peer. On the meditative mind of Goethe on one occasion dawned the bright idea, that the flower of a plant is not, as is commonly supposed, an added or separate organ, but only the highest development, or rather transformation of its leaves — that all the parts of a plant, from the seed to the blossom, are mere modifications of a leaf. This one idea has done more to lift the veil of mystery from nature, and to interpret the plans and purposes of the Creator, than all the previous labours of botanists. It shows us order in the midst of confusion; simplicity in the midst of apparently inextricable complexity; unity of plan amid endless diversity of form. Thoreau, watching the leafy expansions of frost vegetation on the window pane and on the blades of grass, declared that "the Maker of this earth but patented a leaf." He traced the leaf pattern throughout all the kingdoms of Nature. He saw it in the brilliant feathers of birds; in the lustrous wings of insects; in the pearly scales of fishes; in the blue-veined palm of the human hand; and in the ivory shell of the human ear. The earth itself, according to him, is but a vast leaf veined with silver rivers and streams, with irregularities of surface formed by mountains and valleys, and varied tints of green in forest and field, and great bright spaces of sea and lake. This, however, is a mere transcendental idea when thus applied to all the departments of nature; it is scientific truth only when confined to the vegetable kingdom. But the unity of which it speaks may be traced everywhere. All the recent discoveries of science, both as regards the forms and the forces of matter, have an obvious tendency to simplify greatly the scheme of nature, and reduce its phenomena to the operation of a few simple laws; and in this respect they have a profound theological significance. Amid these brilliant generalizations, we cannot stop short until we have reached the highest and sublimest generalization, and nature has led us by such great altar steps up to nature's God. The theory of the leaf, as lying at the basis of the vegetable kingdom, requires more particular explanation. All plants are produced from seeds or buds; the one free, the other attached; the one spreading the plant geographically, the other increasing its individual size. Carefully examined, the seed, or starting point in the life of a plant, is composed of a leaf rolled tight, and altered in tissue and contents, so as to suit its new requirements. The real character of a seed may be seen in the germination of a bean, when the two leaves of which it is composed appear in the fleshy lobes or cotyledons which first rise above ground, and afford nourishment to the embryo. The bud, or epitome of the plant, which is physiologically co-ordinate with the seed, is also found to consist of leaves folded in a peculiar manner, and covered with tough leathery scales to protect them from the winter's cold; and in spring it evolves the stem, leaves, and fruit — in short, every structure which comes of the seed. Further, all the appendages borne on the stem — such as scales, leaves, bracts, flowers, and fruit — are modifications of this one common type. Flowers, the glory of the vegetable world, are merely leaves, arranged so as to protect the vital organs within them, and coloured so as to attract insects to scatter the fertilizing pollen, and to reflect or absorb the light and heat of the sun for ripening the seed. Stamens and pistils may be converted by the skill of the gardener into petals, and the blossoms so produced are called double, and are, therefore, necessarily barren. The wild rose, for example, has only a single corolla; but when cultivated in rich soil, its numerous yellow stamens are changed into the red leaves of the full-blown cabbage rose. That all the parts of the flower, the calyx, corolla, stamens, and pistils, are modified leaves, is proved by the fact that it is by no means uncommon for a plant to produce leaves instead of them. We come next to the fruit, which, in all its astonishing varieties of texture, colour, and shape, is also a modified leaf; and it is one of the most interesting studies in natural history, to trace the correspondence between the different parts of structures so greatly altered and the original type. In the peach, for instance, the stone is the upper skin of a leaf hardened so as to protect the kernel or seed; the pulp is the cellular tissue of a leaf expanded and endowed with nutritive properties for the sustenance of the embryo plant; and the beautiful downy skin on the outside is the lower cuticle of the leaf with a sun bloom upon it, the hollow line on one side of the fruit marking the union between the two edges of the leaf. So also in the apple; the parchment-like core is the upper surface of the leaf, and the flesh is the cellular tissue greatly swollen; in the orange, the juicy lips enclosing the seeds are the different sections of the leaf developed in an extraordinary manner; while through the transparent skin of the ripe gooseberry, we see the ramifications of the leaf veins, conclusively proving its origin. In all the parts and organs of the plant then, from the seed to the fruit, we have found that the leaf is the type or pattern after which they have been. constructed; and those modifications of structure, colour, and composition, which they exhibit, are for special purposes in the economy of the plant in the first place, and ultimately for necessary services to the animal creation, and even to man himself, to whom the sweetness of the fruit and the beauty of the flower must have had reference in the gracious intentions of Him who created them both. On the leaf itself may be read, as unmistakeably as on a printed page, its morphological significance. As the architect draws on a chart the plan of a building, so the Divine Artist has engraved on the leaf the plan of the organism, of which it is the only essential typical appendage. Each leaf in shape and formation may be regarded as a miniature picture, a model of the whole plant on which it grows. The outline of a tree in full summer foliage may be seen represented in the outline of any one of its leaves; the uniform cellular tissue which composes the flat surface of the leaf being equivalent to the round irregular mass of the foliage. In fact, the green cells which clothe the veins of the leaf, and fill up all its interspaces, may be regarded as the analogues of the green leaves which clothe the branches of the tree: and although the leaf be in one plane, there are many trees, such as the beach, whose foliage, when looked at from a certain point of view, is also seen to be in one plane. Tall pyramidal trees have narrow leaves, as we see in the needles of the pine; while wide-spreading trees, on the other hand, have broad leaves, as may be observed in those of the elm or sycamore. In every case the correspondence between the shape of the individual leaf and the whole mass of the foliage is remarkably exact, even in the minutest particulars, and cannot fail to strike with wonder everyone who notices it for the first time. Examining the leaf more carefully, we find that the fibrous veins which ramify over its surface bear a close resemblance to the ramification of the trunk and branches of the parent tree; they are both given off at the same angles, and are so precisely alike in their complexity or simplicity, that from a single leaf we can predicate with the utmost certainty the appearance of the whole tree from which it fell, just as the skilful anatomist can construct in imagination, from a single bone or tooth, the whole animal organism of which it formed a part. In connection with this general typical character of the leaf may be viewed its particular typical significance, as representing the three great classes into which the vegetable kingdom has been divided. That it is possible to determine from the leaf alone, or even from the smallest fragment of it, what position to assign to any given plant in our systems of classification, is surely owing to the fact that the plan of the leaf is the basis upon which all vegetation, as a distinct kind of life, has been constructed. There is no end to the diversity of shape which leaves display; almost every species of plant having a different kind of leaf. But it almost never occurs to us to ask ourselves the object of this variation of shape. We regard it as a thing of course, or refer it to that boundless variety which characterises all the works of nature, in accommodation, we proudly but foolishly suppose, to man's hatred of uniformity. But observation and reflection will convince us that there is a special reason for it; that the shapes of leaves are not capricious or accidental, but formed according, to an invariable law, the council of His will with "whom there is no variableness or shadow of turning." In the first place there is a morphological reason for it. The shape of leaves depends upon the distribution of the veins, and the distribution of the veins upon the mode of branching in the plant, and the mode of branching in the plant to its typical character as an exogens or endogens, and its typical character brings us back again to the leaf. When the leaf is simple, the branching of the stem and the blossoms is simple; and when the leaf is compound, all the parts of the plant are also compound. But besides this morphological reason for the immense variety of leaf shapes, there are also teleological and geographical reasons. Leaves are adapted not only to the typical character of the whole plant, but also to the character of the situation in which it grows. They are, moreover, exactly constructed to shade and shelter, or freely expose to the light and air, the plants on which they are found, and to transmit the dews and rains which fall upon them to the young absorbing roots. He who studies attentively and reverently the numerous wonderful modifications in shape and structure which the typical leaf undergoes, to suit the varied circumstances of plants, will be brought by this study, more closely than by anything out of the Bible, into the personal presence of Him who said, "My Father worketh hitherto, and I work." I have often had a train of reflections of the most profitable kind awakened in my mind by simply looking at the common water ranunculus, whose white flowers cover the surface of many of our quiet rivulets in June, and observing that the leaves floating or the top of the water were round and broad, whereas the lower ones, immersed in the stream, were divided into a vast number of linear segments, so as not to impede the current or be torn by its force. Even in gazing on the common gorse or whin of our hillsides — a plant, apart from the golden glory with which the summer halos it, not very attractive to the lover of beauty — I have been often struck with the same adaptation to the tempestuous currents of the air, in its sharp needle-like leaves and stems — a proof of God's care over the homeliest thing, giving more honour to that which lacked it. But feelings of greater interest still will be excited by the more wonderful adaptations which we see in the tropical plants growing in our conservatories. The mimosa, peculiarly exposed to injury, sensitively drooping its leaves at the slightest touch; the pitcher plant, holding up its leaf goblets filled with water to refresh it in the thirsty desert; the leaf of the Venus' flytrap of North America, closing together on its prey by turning on its mid-rib as on a hinge; the leaf of the cactus growing on the dry plateaus of Mexico, fleshy and juicy, and having no evaporating pores in its skin, so that the moisture imbibed by the root is retained; the gigantic leaf of the royal water lily of South America, furnished on the underside with outstanding veins of great depth, acting as so many supporting ribs: these and a thousand other instances almost equally remarkable, that might be alluded to, attract the most careless eye, and in their strange variations from the typical form, disclose abundant proof of beneficent design. The colours as well as the shapes of leaves are wonderfully diversified, though green is the prevailing hue, and every varied shade of that colour, from the darkest to the lightest tint, is exhibited — and very beautifully, for instance, in the verdure of spring; yet the whole chromatic scale may be seen illustrated in the foliage of plants. Indeed, where it is possible to see specimens of the whole vegetable kingdom growing together, an autumnal forest would not exhibit greater varieties of coloured foliage. In some plants the leaves are as beautiful as the flowers of other plants: and these are now cultivated and grouped with great effect in our conservatories. A greenhouse full of beautifully foliaged plants, is as attractive as one stocked with gay blossoms. It is a remarkable circumstance, that when the leaves are dressed in bright crimson, or golden, or silvery splendours, the flowers are almost invariably sombre in hue, and insignificant in form and size. What purposes such beautiful leaves may serve in the economy of vegetation, we cannot in every case find out satisfactorily. It may be to absorb or reflect the light and heat of the sun in a peculiar way, or to guard the vital organs from injury by diverting attention from them. In orchids and other plants, the blossoms are gorgeously coloured and peculiarly shaped, in order to attract insects, without whose agency the species could not be fertilized or propagated. But in plants where the foliage is large and beautiful, and the flower minute and sombre, it seems as if Nature wished to conceal her vital processes, lest they should be frustrated or injured by animals. Probably, also, the same law of compensation may be illustrated in the case of coloured leaves, as in the irregular corolla of flowers, where the odd petal has a different and much brighter colour, as in the common pansy. Do not these curious plants, that among their leaves of light have no need of flowers, resemble those lure human plants, that develope all the beauties of mind and character at an exceptionally early age, and rapidly ripen for the tomb? They do not live to bring forth the flowers and the fruit of life's vigorous prime; and therefore God converts their foliage into flowers, crowns the initial stage with the glories of the final, and makes their very leaves beautiful. By the transfiguration of His grace, by the light that never was on sea or land, He adorns even their tender years with all the loveliness which in other cases comes only with full maturity. (H. Macmillan, LL. D.) There was not a man to till the ground. — Parallel Verses KJV: And every plant of the field before it was in the earth, and every herb of the field before it grew: for the LORD God had not caused it to rain upon the earth, and there was not a man to till the ground. WEB: No plant of the field was yet in the earth, and no herb of the field had yet sprung up; for Yahweh God had not caused it to rain on the earth. There was not a man to till the ground,