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worship in existence—for this regular order, let it be ever so simple, is itself a power, and, therefore, even greater uniformity should be striven for, both in the public worship of the same church, and in that of all Congregational Churches; and again, that as forms of worship are matters of growth, springing from the hearts, wants, faith, and emergencies of the people through long periods of time, they cannot be transferred, at the pleasure of the individual church or pastor, from one to another denomination whose types or ideas of worship essentially differ. We cannot adopt the episcopal form or liturgy without becoming Episcopalians. Whatever form of worship we have, it must be genuinely our own.

The question not yet satisfactorily settled is, whether in an essentially unliturgical form of worship, the elements of power, truth, and beauty that a liturgical form may possess, may not be equally secured, and the evils which are wrapped up in the latter system may be at the same time avoided? This is the interesting and difficult question, which, in the presence of an advancing civilization, of a more general cultivation of the æsthetic sense, of the power of the human element which is making itself more and more felt in all religious things, of the lowering of the high tone of primitive piety, or its assumption of other phases that are apparently a decay of the highest spiritual life—this is the practical question that the Congregational Churches have now to meet and work out.

The time may come when in all these questions of church worship, polity, benevolence, and life, Christian men of all bodies and sects may be able to rise above their denominational platforms, and have regard only to the interests of their “ common faith ;” when they may be able to aid each other in arriving at the truest method of serving and glorifying God; when one body of Christian worshippers may impart to another whatever portion of truth or power it is more peculiarly in possession of; when the name “Christian” may be above every sectarian name, and all who love Christ may delight to walk, and counsel, and toil, and worship together.

THE COLOURS OF PLANTS.

None can so fully appreciate the invigorating, freshening, and at the same time soothing influence of the earth's green covering as those who have dwelt for months amid the red and yellow glare of the sandy desert, where the scanty shrubs are themselves almost brown, and where nothing is green save the pale emerald blush of the morning and, sometimes, of the evening sky. There is great grandeur in the colouring of waste rocky cliffs, desolate mountain ridges, and sandy, gravelly plains. The eye is filled again and again with scenes of intensity of hue such as Holman Hunt has painted in his picture of the Scapegoat. As the day broadens up in the morning and fades away again into night, every variety of tone, every shade of red and yellow and brown, flits in turn over terrace and precipice. The cold grey cliff of the early morn warms into bright ochre at noon, glares as dull red as the sun declines, blends in a rich brown with the evening shades, and at last stands out a dull black mass beneath the twinkling light of the stars. Nothing can be more glorious than to watch the birth of colour far and near in the early hours of the day, while the morning star is still bright, unless it be to sit for the half-hour after the sun goes down and

rosy hne of the after-glow thrown on the distant hills. But the glory and the grandeur are too great a strain; the very depth and strength of the variety exhaust the mind. Where the yellow and the red are left behind, and one comes back again to a land of verdure, and sees stretching before one an expanse of grass, and growing corn, and spreading trees, it seems as if the toil of sight as well as travel were over; one feels that green pastures are one with still waters; that in a vision of green, and green only, can the eye rest with perfect content.

There can, in fact, be no doubt that the prevalent, the almost universal colour of the vegetable kingdom, is the one which is most pleasing, most suited to the human eye; and many persons would be content to let the matter rest there. It happens, however, in this, as in so many other instances where we seek for reasons, as we call them, of the existence of natural phenomena, that if we are satisfied with the first that comes to hand, we miss others, often deeper and more important.

There are reasons for the greenness of plants for other than

gaze on the

the convenience or pleasure of the eye of man, reasons which would suffice to make plants green in a world where he was not. There are other colours to be met with in plants, the colours of gay flowers and autumnal changes; but all these stand on a wholly different footing from green; for it is possible that they may serve no other purpose than that of appearance, have no other end than beauty. Green is not only the most beautiful, it is also far the most useful of all vegetable colours; it is not only the queen of hues, it is also of absolute importance to the prosperity and very existence of the plant.

The green colouring matter of plants differs from other vegetable pigments in its anatomical disposition, in the manner in which it is laid up in and built into the leaf or stem. We need hardly say that of all the organs of a plant the leaves are those which are particularly and exceptionally green. All true leaves are green, at least in part; the stem may have a slight coat of green, but not necessarily, except in those plants, such as the cactus, where the stem fulfils all the functions of leaves. If we take a thin section of any leaf, or piece of green bark, and place it under the microscope, we find that it is built up of little chambers or cells, within which the green colouring matter is stored up in the form of little round or oval lumps. The watery fluid and the living jelly or protoplasm of each cell is colourless, or at least not green. The whole of the greenness is confined to these little lumps, which are dragged from spot to spot within the cell by the movements of the ever-moving protoplasm, and which have received the name of chlorophyle bodies. There is no green in the vegetable kingdom which is not confined in one of these bodies. Nearly all the other colours of plants, the reds, blues, and yellows of the flowers, exist as coloured watery contents of cells; none of them occur in an organized form like that of the chlorophyle bodies.

As we study under the microscope these leaf-cells and their green inhabitants we find that the chlorophyle body, which at first is a mere speck, as it in course of growth gets wider and bigger, comes somehow or other to have within itself in turn a white spot. This spot, in time growing larger and larger, puts on characters of its own, whereby the botanist is able to recognize it as a specimen of that chief product of vegetable labour, the starch-corpuscle. In the leaf-cell comes the chlorophyle-body, and in the chlorophyle-body comes the starch-corpuscle. The living slime or jelly, the ever-moving active protoplasm of the cell, manufactures the chlorophyle, the chlorophyle manufactures the starch. In no other part of the plant, except in the green chlorophyllic cells of the leaves and other green organs, is there any starch actually made, and they do nothing else much but make it. As fast as they manufacture it, it is carried off in the sap to other parts, and stored up, according to the requirements of the individual plant, in the stem, in the buds, in the swollen tubers and knots of the roots, or in the floury treasures of the seed. To us and to other animals starch is a necessity for daily food, and we seek it in flour, in corn-seeds, in roots, in stems, or in leaves. Whencesoever we get it, every starch-corpuscle that we eat, or otherwise use, was born in the bosom of a chlorophylebody in some green and leafy cell. The green of a plant is good for the eye, but not for the eye only. Its qualities are doubly blessed : it feeds as well as pleases ; it helps to make the eye which afterwards its rejoices.

It is the duty of the leaf-cell to manufacture first green-stuff, and then starch; but it can do this only under certain conditions. It must have light. Or, rather, it is light which, working through the leaf-cell, builds up and joins together the elements, first of chlorophyle, and then of starch. Without light there can be no greenness and no starch. The seed, buried and springing up in the dark earth, puts forth its shoots, but for a while makes no starch. It has no colour, and the structures that it builds up are formed entirely at the expense of the material hoarded in the seed. When, however, the tips of the tender leaves break through the soil, and begin to feel the rays of the life-giving sun, then the atoms of its stuff run together into the green lumps of chlorophyle, and soon after the manufacture of starch begins. When a plant is kept in darkness, it grows pale, it becomes blanched, the chlorophyle ceases to be formed, the starch is no longer made. Whatever growth takes place is carried on entirely out of the material amassed while the plant was still enjoying the light of day. So, too, when the sun sets, and the mantle of darkness covers the earth, these busy laboratories of green cells are hushed in quiet : they rest from their labour until the light returns.

There is a token whereby we may learn whether these cells are at work or no. While they are at their toil, they are busily engaged taking in some of that carbonic acid which is always floating about in the earth's atmosphere. They seize upon this substance, tear its carbon from its oxygen, bind the carbon in their prison, and give back the oxygen to the air. This they do so long as light is present to them. When the light vanishes, their power over carbonic acid goes too. They then become like all other living tissues, and pursue the inverse process of consuming oxygen and producing carbonic acid.

Strictly speaking, they-the cells--are not the active agents in the matter; they are only instruments in the hands of Light. We may represent to ourselves the atoms of carbon and of oxygen, when existing separate in nature, as longing to be united and yet kept apart by a certain force. When they do unite together (and so form carbonic acid) the force which was previously engaged in keeping them asunder is now free to act in some other way. A man who is occupied in preventing two dogs from fighting, holding one with one hand and the other with the other, as soon as he lets them go, has his hands free for other work. The dogs meanwhile grapple with each other. So is it with carbon and oxygen. Before carbon has become united with oxygen, while wood or coal, which are made of carbon, are being burnt that is, are being oxydized or united with oxygen-a certain force is set free, which force we generally call heat

, and use to warm our bodies or to drive our engines and mills. Similarly, in order to separate carbon from oxygen, in order to loose them from the grapple which we call carbonic acid, some force must come in and divide them and keep them, so to speak, at their atoms' arm length. Such a force is light, and such a work of separation is the sun constantly doing in the green cells of plants. Force, in the shape of light, which is visible heat, and heat, which is invisible light, is ever streaming upon our earth from the sun, and hiding itself among our plants. Falling on the expanded leaves it there grapples with carbonic acid,

wedges itself in between the locked atoms, rives them, throws aside the oxygen, and, so to speak, buries itself with the carbon in the form of starch amid the tissue of the leaf-cell. The starch afterwards either remaining as starch becomes the food of man or of some animal, and gets burnt up in the fire within the body, or getting converted into wood-it may be, into coal—is burnt as fuel in the fire without. Sooner or later, in some furnace or other, the light which buried itself in the cell enters once more on a free existence in the form of heat. To make the history complete we ought to say that light treats the hydrogen and oxygen of water in the same way as it treats the carbon and oxygen of carbonic acid.

Of course, when the light buries itself in the leaf-cell, and hides itself in the starch, it no longer bears the name of light, or, rather, it no longer is light. And here we see the meaning of the green colour of plants. Light, as it comes from the sun, is white, though mixed up of many colours. There are all the colours of the rainbow in it, though we have to adopt particular means to render them visible. The various colours of the spectrum have different qualities and different uses. They are not all of equal value in binding carbon into starch. Those which

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