In similar beautiful adaptation to outward circumstances, we find that the stem of the graceful palm tree is high and slender, but built up of unusually tough, woody fibres, so that it sways gently to and fro in the breeze, and yet resists the fiercest storms, while the lofty bare trunk gives free passage to every breath of air, and the broad flat top tempers the burning sun and shades the fruit hanging down in rich clusters. The solemn and imposing fir tree, on the other hand, branches low, but just high enough to let man pass beneath, and then drops its branches at the extremities, like a roof, exposing on terrace after terrace, its small fruit to all aspects of the sun, and, in winter, letting the heavy snow glide down, on the smooth polished leaves. If the palm were a pyramid like the pine, it would fall before the first storm of the tropics; if the pine were tall and shaped like a broad parasol, the snow and ice of the north would break it by their heavy weight.

It is this part of the plant which gives it, in common life, its proper rank and name in the vegetable kingdom. When the stem is not woody and dies after the flowering season, we speak of it as an herb, while a shrub has already a greater size and a stem that branches at the base. The tree lifts its head high into the air, and divides mostly above. The stems of climbers and creepers are long, thin and winding, whilst runners crawl along the ground or beneath it, and produce new plants at their termination.

The stem has frequently a decided tendency to grow spirally; in creepers it is twisted from the root to the end, the better to enable them to lay hold of and to embrace the objects around which they twine. So it is in all climbing plants and their tendrils, which derive from this peculiar structure such strength, that they serve in South America to form long, slender, but perfectly safe bridges over broad rivers. Even large trees have frequently the same spiral tendency, as we see in many a blasted trunk in our forests, or when we attempt to remove the bark from a cherry tree, which will not tear straight and must be torn off in a spiral.

In the stem, also, we see the main differences of the growth of various kinds of wood in a beautiful variety of grain and wavy lines. Its outside is protected by bark, sometimes smooth as if polished, in others, as in the pine, carved in huge square pieces; hard and invulnerable as stone in the cypress, but cut and cracked in the elm. Most mountain trees have

their bark deeply furrowed with numerous channels, to lead the moisture of rain and dew down to the rocky home of their deep buried roots. Dark' colored and soft in tropic climes, to resist the heat, it is white as snow in the Arctic regions, and in northern trees, as birches and willows, in order to reflect what little heat is found in such high latitudes. The bark is, moreover, the last part of a plant that decays, and in some trees may be called almost indestructible. Thus Plutarch and Pliny both tell us, that when, four hundred years after the death of the great lawgiver Numa Pompilius, his grave was opened, the body of the king was a handful of dust, but the delicate bark, on which his laws had been written, was found uninjured by his side.

Not all stems, however, are of the same firm, upright structure. Nature shows beauty not only in the forms themselves, but perhaps still more in their endless variety. In the cactus family they are represented by what we commonly, though erroneously, call their leaves, viz., fleshy expansions, tumid with watery juice, and clothed with a leathery cuticle, instead of bark. Of all cactuses, but one has real leaves all others possess little more than miserable substitutes in the form of tufts of hair, thorns and spines. These only, as far as they go, are their true leaves. The stems, it is well known, display in this same family an unusual variety of odd, outlandish-looking shapes. Now they rise, under the name of torchthistle, in a single branchless column to the height of forty feet; and now they spread their ghastly, fleshless arms in all directions, like gigantic funereal candelabras. The melon-cactus imitates in shape and bristling spines the hedgehog to perfection, whilst the so-called mammilearia are smooth or ribbed globes of all sizes. Others, at last, grow longitudinally, like the long whip-like serpent cactus, which swings ominously from the trees on which it lives a parasite. Nature, however, has made them ample compensation for their uncouth appearance and gloomy, wretched aspect, by giving them a profusion of flowers of unsurpassed brilliancy.

The snake-like form of the last mentioned cactus is still more strikingly prosented in the stem of the lianes of South America. They are almost entirely stem. Stretched out like the strong cordage of a vessel, on which tiger-cats run up and down with wonderful agility, or winding serpent-like in and out, now as cords and now like flat straps, they extend frequent

ly more than a hundred feet, without leaves and without branches. In the primeval forests of the tropics they may be seen hanging from tree to tree, often ascending one, circling it until they choke his life's blood in him-then wantonly leaping over to another-next falling in graceful festoons and then climbing up again to the topmost summit of a palm, where, at last, they wave perhaps their bunch of splendid flowers in the highest, purest air. Repulsive in themselves, these lianes also grow beautiful by the contrast they present with the sturdy monarch of the forest, around which they twine, a contrast which yet, as every thing in nature, produces harmony. How different are these stems again from the beautiful structure of the various grasses. Here a slender column rises, sometimes to the height of a few inches only, as in our common mountain grasses, and then again, in the bamboo, to a towering height, waving their wide-spread tops in the evening breeze, or growing like the gigantic grasses on the banks of the Orinoco, to a height of more than thirty feet, where they have joints that measure over eighteen feet from knot to knot, and serve the Indians of that country as blowpipes, with which they kill even large animals. And yet the delicate graceful tissue of all these grasses resists by their wondrous structure the storm that would break columns of granite, of the same height and thickness! Nature knows full well that a slender, hollow tube, with well strengthened walls, the most solid parts being placed outside, is the best form to give firmness and solidity to such structures. Hence it is that these delicate walls are hardened by a copious deposition of silica, so that e. g. a kind of rattan has solid lumps of it in joints and hollows, and will readily strike fire, with steel; and the so-called Dutch rush, a horsetail moss, is largely imported from Holland for its usefulness in polishing furniture and pewter utensils. The grass which grows on less than half an acre of land is said to contain flint enough to produce, when mixed with sand and by the aid of the blowpipe, a glass-bead of considerable size; and after a number of haystacks, set up by the river side, had once been struck by lightning and burned, large lumps of glass were found in their place. Wondrous indeed are the works of the Almighty, and well can we understand the deep pathos with which Galileo, when questioned as to his belief in a Supreme Being, pointed at a straw on the floor of his dungeon and said: "From the struc

ture of that little tube alone would I infer with certainty the existence of a wise Creator!"

Other stems grow under ground, like our bulbs, whose scales are the real leaves of the plants, where they alone, well protected from cold and tempest, live through the dreary winter season. Or they are hid by the water in which they live, and then frequently reach an almost incredible length. Some marine Algae have been found more than fifteen hundred feet long; they branch off as they approach the surface, until they form a floating mass of foliage, hundreds of yards square. These stems resemble cords in every variety of form and twist, and are used by the natives of the north-west coast, where they are most frequently found, as fishing lines-while others of the same kind are dried to serve as siphons, or are formed by the natives into trumpets, with which they collect their roving cattle at nightfall. The most remarkable stem, however, of all more common plants, is probably that of the Valisneria, an aquatic plant which grows at the bottom of rivers. It consists of long, elastic cords, twisted like a corkscrew, and sends some branches up to the surface, while others remain below and are completely submerged. When the flowering season approaches, the plant shows an instinct so closely approaching conscious action as to startle the careful observer. Some flowers also are produced below, where they cannot exhibit the beauty of their frail blossoms; these begin to stretch and to twist, as if they longed for the bright sunshine above, and at last they 'succeed in breaking loose from their dark, gloomy home. In an instant, they rise to the surface, being lighter than water, expand there under the benign influence of light and air, and mingle their dust with other flowers, which are already floating there. This "high" life continues until the seeds are beginning to ripen, when the elastic stems contract once more, and, with like wonderful instinct, carry the seed vessels down and bury them in the watery bed of the stream, where alone they can hope to find all the requisites for their future growth and welfare.

The stems or trunks, finally, indicate in all long-lived plants the age with unerring accuracy. Their growth being limited only by external causes, the years of trees are seen in their size, and this union of age with the manifestation of constantly renewed vigor, is a charm peculiar to the Life of Plants. Animals, however curious, beautiful or imposing,

have still a limited size and figure-plants alone grow without limit, and bring forth new roots and new branches as long as they live. This gives to very ancient trees, especially, a monumental character, and has ever-inspired nations with a kind of instinctive reverence, which from the days of antiquity to our own has often degenerated into downright worship. Who has not heard of the oaks of Mamre and the pilgrimages made to them from the time of Abraham to that of Constantineor of the far-famed cedars of Lebanon, which have always been distinguished as objects of regard and veneration, so that no threat of Sennacherib was more dreaded, than that he would level them to the ground? Herodotus dwells with delighted sympathy on the marks of respect with which Xerxes loaded the famous plane tree of Lydia, while he decked it with gold ornaments and intrusted it to the care of one of his ten thousand "Immortals." As forest trees increase by coatings from without, the growth of each year forming a ring round the centre of the stem, the number of years is usually ascertained-since the well-known author Michel Montaigne first started this theory-by counting the concentric rings. Care must, however, be had not to forget, that some trees begin to form these only after several years' growth, and that, whilst northern trees shed their leaves but once a year, and therefore add but one ring during that time, those of the Tropics change their foliage twice or thrice a year, and form as many rings. This renders the age of such trees, as were heretofore considered the oldest, somewhat doubtful; still there are some remarkable cases of longevity well authenticated. Humboldt measured a gigantic dragon tree near the peak of Teneriffe, and found it possessed of the same colossal size, forty-eight feet round, which had amazed the French adventurers, who discovered that beautiful island more than three centuries agoand yet it still flourished in perpetual youth, bearing blossoms and fruit with undiminished vigor! Some yew trees of England, and one or two oaks, claim an age of from one thousand four hundred to three thousand years, and would, if their claims were substantiated, be the oldest trees in Europe-but a famous Baobab on the banks of the Senegal is believed to be more than six thousand years old, in which case its seed might have vegetated before the foot of man trod the earth! Its only rival is a cypress tree in the garden of Chapultepec, which Humboldt con

siders still older; it had already reached a great age in the days of Montezuma. A curious old age is that of a rose-bush which grows in the crypt of the cathedral of Hildesheim, in Germany; it was there planted by the first founder of the church, and is expressly mentioned in the MS. in which his donation and the building itself is described; it also flourishes still, and bears as fragrant roses in these years of change and revolution, as eight hundred years ago, when Germany was one and great!

Most plants are accustomed-we hope not for their sins-to cover themselves like our first parents with leaves, and it is well established now, that the plant, properly speaking, consists only of stem and leaves-all other parts, like buds, flowers and fruits, being only modified forms of leaves. These are mostly green, and the depth of their color is an indication of the healthfulness of their action. But there are a hundred shades, and the color invariably contrasts most beautifully with the background, on which the plants appear. The humble moss shines with its brilliant emerald green on the dark sides of rocks, whilst mushrooms display their gorgeous scarlet and orange between the sombre rugged roots of the trees, under whose shadow they love to dwell. The glossy color of the ivy looks all the more cheerful by the gray bark or crumbling ruins, which it hides with the folds of its warm mantle, and vies with the carpet of verdure that vines spread over old turrets or the fallen trunks of ancient trees, whilst in Fall they reflect permanently the gold and purple of the setting sun. But, here also, beauty is not given to all with the same lavish hand. Whilst the queenly Victoria floats its richly-tinted leaves in gorgeous beauty on the dark mirror of calm, shady lakes, the poor lichens of the north shiver in their scanty coat: gray and withered in the shade, they look, when lighted up for a brief noonday time, like gigantic snowcrystals, and cause a chilly shudder. Australia, where all extremes meet, from the bird-fashioned quadruped to the millionaire convict, the leaves of trees and bushes have a leathery look and are oddly twisted, turning their edges up and down, instead of standing horizontally as with us. They afford no shade, and are covered with a white, resinous powder, which gives them a most dismal and pallid appearance. Yet-whatever form

In

leaves may assume their wonderful adaptation to their great duty strikes us in all plants alike. The immense extent

of surface, which they present to light and heat, the thinness and delicacy of their structure, the microscopic beauty of their minute apertures, their power of breathing in and out-all answer admirably the great purpose of exposing the crude sap, that rises from the root, to the air and the sun, to be by them digested into highly nutritious food.

All leaves change their color in autumn, when a peculiar chemical change goes on in their substance, and takes the bright, fresh green from them, to leave them in sad-colored livery, or to clothe them, as a parting gift, in the brilliant drapery of an Indian summer. It is then that, especially in American woods, a combination of hues is produced which no painter can hope to imitate, when the maple burns itself away, and "all the leaves sparkle in dazzling splendor with downy gold colors dipped in heaven."-Not a less variety may be perceived in the shape of leaves. Needle-shaped in northern evergreens, they are there gathered like tiny brushes to collect at every point whatever heat and moisture may surround them. Plants growing in arid places or high mountains have leaves shaped like cups, with broad channels to conduct the precious fluid to their roots. In trees bearing cones they are dry, pointed and narrow; they seldom rustle, being silent; but, as a compensation, they are ever green. Their high polish enables them to reflect what little heat they can gather in northern lands, whilst the light may still pass between them with ease. On catkin-bearing trees they are broad and tender, so that the gentlest wind gives them motion and sound, a charm wholly wanting in evergreens; but their time is short, and they perish after a season! As we approach the Equator, we find leaves without polish, so as to reflect no heat, placed horizontally to form a shading roof. They grow broader and larger, with every degree, until the cocoa-palm has them more than one foot square, and a single leaf of the tallipot-palm of Ceylon can cover a whole family. Those of the waxy palm of South America are, moreover, so impermeable to moisture, that they are used as coverings for houses, and have been known to stand all the vicissitudes of the weather for more than twenty years, without being renewed. They thus form a screen by day, a tent by night, and become eminently useful in a land which is half the year burnt by a scorching sun, and the other half completely under water. In like manner will leaves change according to the wants of the tree, whose ornament

and best servants they are at the same time. The oak of our mountains has thick, broad leaves-that of the sea-shore, which we call willow and live oak, is satisfied with thin narrow leaves. The honeysuckle changes them at will into tendrils, the pea into hands with three or five fingers, with which to grasp its support, this only when it has reached a certain height, and needs the latter; the passion flower converts them into a corkscrew, whilst the common nasturtium is content with a simple hook at the end of the leaf. Their arrangement also around stem and branches is not left to accident: a distinguished mathematician of our Cambridge once astonished a large and learned audience not a little, when he informed them that plants knew mathematics, and arranged their leaves according to fixed rules. A spiral line drawn from the base of one leaf, around the stem, to that of another, shows regular intervals between them, which vary in different plants, but are in each carefully and strictly observed.

The great purpose of life in leaves is to carry on their most active and important vital function—their respiration. They are the lungs of plants, not condensed, as in man, in one organ, but scattered independently in countless numbers over the branches. For the purpose of breathing they are endowed with innumerable and often invisible little openings, commonly on both sides-in aquatic plants, however, whose leaves float on the surface of the water, only on the upper side. In the cactus tribe they are almost wholly wanting, hence the latter are so succulent, because they retain all the fluid that their roots have sucked up, and exhale nothing. Their activity is, of course, a twofold one, as they both take in and give out, without ceasing. They inhale atmospheric air, appropriate its carbon for the formation of their juices, and return the separated and disengaged oxygen in the form of gas. This process, however, can only go on during daytime, as light is indispensable-and is performed by all the green parts of a plant alike. It is this incessant labor, which makes plants not only an ornament of our earth and a food for man and cattle, but renders them so eminently useful in the great household of Nature. They absorb the carbon, that man cannot breathe, and furnish, in return, the oxygen, without which he cannot exist; thus virtually, by their industry, rendering the atmosphere fit for the support of Animal Life. Besides the exhalation of oxygen,

the leaves also evaporate nearly twothirds of the water which the roots have imbibed, and sent up to them through the interior of the plant. The moment, however, this now perfectly pure water is exhaled, it is dissolved in the air and becomes invisible to the eye.

Another duty, which the leaves of plants perform with still greater energy, is the drawing of water from the atmosphere. They drink it in, from the first moment of their short life, to the last day, by all possible means and contrivances. The young leaves, as yet wholly or in part rolled up, are but so many cups or spoons, turned to heaven to gather all the moisture they can hold. As the young. plants grow, they unfold leaf after leaf, and all perform the same duty with the same eagerness. From the cedar of Lebanon down to the bashful violet, each plant holds forth its gigantic mass of foliage or its tiny goblet, to have its share of the precious moisture. All are greedy consumers of water, and know how to obtain it, by some peculiar, as yet unknown process, even in such regions of the Tropics, where for half the year no cloud darkens the ever-serene sky, and where not even dew is given to refresh the panting vegetation. Their power, in this respect, is as great as it is mysterious. The most succulent plants of the Tropics cling to the faces of barren cliffs, or rise from dry, dust-like sand. It is true, their leaves contain both caoutchouc and wax, and are covered with a thin layer of these substances, as with a water-proof cloak, to prevent evaporation under a burning sun. Some plants, however, support themselves not only, but actually increase in weight when suspended in the air, and unconnected with any soil, as the common houseleak and the aloe. The so-called air-plant, perhaps the most remarkable of the whole vegetable kingdom, is but a single leaf, without stem or root, and yet it is able to maintain life, to grow and to blossom, if only hung up in a warm and damp atmosphere, though it be not even in contact with any other substance. It puts out buds, these become leaves, drop tiny roots into the air, and soon exist as independent plants.

And here again we cannot help observng, how quietly the work of Nature is going on, unsuspected and unheeded by

us.

The innumerable leaves of our forest and arbor trees form a vast summer laboratory, in which the great work of plants is incessantly continued, and which contributes, to an incalculable extent, to the support and the health of all animal

existence. They afford us thus another of the thousand proofs of creative design, which we may, at a glance, obtain from the vegetable world. They labor and work for themselves apparently all the while, but render the earth and all life thereon invaluable service. Even when they greedily draw up all moisture by roots or leaves, they become our benefactors. The despised mosses hold up their little cups to drink in the waters of heaven, and make most ample return for its bounty. They clothe the steep sides of lofty hills and mountain ranges, and their densely-crowded delicate leaflets attract and condense the watery vapors constantly floating in the air, and thus become the living fountains of many a proud stream. The tall trees of the forest draw down the rain-filled cloud, as the lightning-rod invites the thunder cloud, and the moisture so distilled is condensed into little streamlets which trickle down from twig and bough, even when the ground is dry and dusty. This gives fertility also to adjoining fields. The heavy, damp air, gathered by the woods, sinks down as fog or mist when the still cool evening comes, and rich dew pearls in the morning on the meadows and refreshes the fields. Trees thus affect materially the climate and general character of countries. Thickly-wooded regions, like our own continent, are colder and more humid than cultivated or broad treeless savannahs; they abound in rain and fertile dew; and to cut down our trees is seriously to impair the supply furnished by them to springs and rivers. Some lands would not be habitable but for trees. In one of the Canaries neither springs nor rivers are found; but there grows a large, tall tree, called with veneration the Saint, in some of the deep recesses of the mountains. It keeps its lofty head all night long wrapped up in mist and clouds, from which it dispenses its timely, never-ceasing moisture in little rivulets, running merrily down from the leaves. Small reservoirs are built for the purpose of catching the precious gift, and thus alone the island is made a fit dwelling-place for

man.

Humbler plants store up water in smaller quantities, but not the less pure or welcome. The melon cactuses have been called the vegetable fountains of the desert, because they conceal under their hideous prickly envelope, covered with dry lichens, an ample supply of watery pith. The great Humboldt tells us graphically, how, in the dry season, when all life has fled from the pampas,, and