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BY PROFESSOR R. HUNT.
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Flowers have been called the stars of the earth; and certainly, when we examine those beautiful creations, and discover them, analyzing the sunbeam, and sending back to the eye the full luxury of colored light, we must confess that there is more real appropriateness in the term than even the poet who conceived the delicate thought imagined. Lavoisier beautifully said—“The fable of Prometheus is but the outshadowing of a philosophic truth—where there is light there is organization and life; where light cannot penetrate, Death for ever holds his silent court.” The flowers, and, indeed, those far inferior forms of organic vegetable life which never flower, are direct dependencies on the solar rays. Through every stage of existence they are excited by those subtle agencies which are gathered together in the sunbeam; and to these influences we may trace all that beauty of development which prevails throughout the vegetable world. How few there are, of even those refined minds to whom flowers are more than a symmetric arrangement of petals harmoniously colored, who think of the secret agencies forever exciting the life which is within their cells, to produce the organized structure—who reflect on the deep, yet divine philosophy, which may be read in every leaf:—those tongues in trees, which tell us of Eternal goodness and order.
The hurry of the present age is not well suited to the contemplative mind; yet, with all, there must be hours in which to fall back into the repose of quiet thought becomes a luxury. The nervous system is strung to endure only a given amount of excitement; if its vibrations are quickened beyond this measure, the delicate harp-strings are broken, or they undulate in throbs. To every one the contemplation of natural phenomena will be found to induce that repose which gives vigor to the mind—as sleep restores the energies of a toil-exhausted body. And to show the advantages of such a study, and the interesting lessons which are to be learned in the fields of nature, is the purpose of the present essay.
The flower is regarded as the full development of vegetable growth; and the consideration of its mysteries naturally involves a careful examination of the life of a plant, from the seed placed in the soil to its full maturity, whether it be as herb or tree.
For the perfect understanding of the physical conditions under which vegetable life is carried on, it is necessary to appreciate, in its fullness, the value of the term growth. It has been said that stones grow—that the formation of crystals was an analogous process to the formation of a leaf; and this impression has appeared to be somewhat confirmed by witnessing the variety of arborescent forms into which solidifying waters pass, when the external cold spreads it as ice over our window-panes. This is, however, a great error; stones do not grow—there is no analogy even between the formation of a crystal and the growth of a leaf. All inorganic masses increase in size only by the accretion of particles—layer upon layer, without any chemical change taking place as an essentiality. The sun may shine for ages upon a stone without quickening it into life, changing its constitution, or adding to its mass. Organic matter consists of arrangements of cells or sacs, and the increase in size is due to the absorption of gaseous matter, through the fine tissue of which they are composed. The gas—a compound of carbon and oxygen—is decomposed by the excitement induced by light; and the solid matter thus obtained is employed in building a new cell—or producing actual growth, a true function of life, in all the processes of which matter is constantly undergoing chemical change.
The simplest developments of vegetable life are the formation of confervæ upon water, and of lichens upon the surface of the rock. In chemical constitution, these present no very remarkable differences from the cultivated flower which adorns our garden, or the tree which has risen in its pride amidst the changing seasons of many centuries. Each alike have derived their solid constituents from the atmosphere, and the chemical changes in all are equally dependent upon the powers which have their mysterious origin in the great centre of our planetary system.
Without dwelling upon the processes which take place in the lower forms of vegetable life, the purposes of this essay will be fully answered by taking an example from amongst the higher class of plants and examining its conditions, from the germination of the seed to the full development of the flower—rich in form, color, and odor.
In the seed-cell we find, by minute examination, the embryo of the future plant carefully preserved in its envelop of starch and gluten. The investigations which have been carried on upon the vitality of seeds appear to prove that, under favorable conditions, this life-germ may be maintained for centuries. Grains of wheat, which had been found in the hands of an Egyptian mummy, germinated and grew; these grains were produced, in all probability, more than three thousand years since; they had been placed, at her burial, in the hands of a priestess of Isis, and in the deep repose of the Egyptian catacomb were preserved to tell us, in the eighteenth century, the story of that wheat which Joseph sold to his brethren.