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We can but imperfectly account for the green, so universal in their herbage; but we may gratefully acknowledge the beneficence of the Creator, in clothing the earth with a colour the most pleasing, and the least fatiguing to the eye. We may be dazzled with the brilliancy of a flower garden, but our eyes repose at leisure on the verdure of a grove or meadow. Abridged from Sir J. E. Smith.
The flower consists of several parts.
The calyx, or flower cup, forms the external integument which protects the bud, before it expands: it consists of several parts, called sepales, resembling small leaves, both in form and colour. These sepales are, in general, more or less soldered together; sometimes so completely, as to form a cup apparently of one piece.
Above and within the calyx, rises the corolla, which is the coloured part of the flower. It is composed of several petals, either separate or cohering, so as to form a corolla of one single piece: in the latter case, the flower is called monopetalous. When the petals first burst from the calyx, and expand in all their beauty, they still serve to protect the central parts of the flower. They are at first curved inwards, forming a concavity around the delicate organs which occupy the centre. This not only shelters them from external injury, but reflects the sun's rays upon them, like a concave mirror; thus rearing them, as it were, in a hot-house. When these parts are full grown, the artificial heat being no longer necessary, and the admission of light and air, being not only safe but advantageous, the petals expand; leaving the internal organs exposed to the free agency of these elements.
At the base of the petals is generally situated an
organ, called the nectary. the bee derives honey.
The most important parts of the flower are those organs which occupy the centre. It is here that the seed, which is to propagate the plant, is lodged, in a vessel called the ovary, or seed-vessel. From its summit rises a little threadlike stalk, called a style; which, at its extremity, supports a small, spongy substance, denominated the stigma. These three parts form a whole, which bears the name of carpel.
This is the store whence
Immediately surrounding the pistils, are situated the stamens; each of which consists of a slender filament, supporting a little bag, or case, called an anther, filled with pollen, which is a species of dust or powder. The anthers, when ripe, burst; and, being more elevated than the stigma, shed their pollen upon it; without which no seed can be perfected.
In some vegetables the stamens are in one flower, and the pistils in another; in others, the stamens and pistils are upon separate plants. In these cases the pollen is conveyed from the one to the other, by means of the wind, or by winged insects, which, in penetrating, by means of their long and pliant proboscis, within the recesses of the corolla, in order to obtain the nectar, cover their downy wings with the pollen. This unheeded burden they convey to the next flower on which they alight; and in working their way to the nectary, it is rubbed off and falls on the stigma. Every insect, however ephemeral, every weed, however insignificant, has its part assigned in the great system of the universe.
In Persia, very few of the palm and date trees, under cultivation, have stamens, those having pistils being preferred, as alone yielding fruit. In the season of flowering, the peasants gather branches of the wild palm trees, whose blossoms contain stamens, and spread them over those which are cultivated, so that the pollen comes in contact with the pistils, and fertilizes the flower.
There were two remarkable palm-trees in Italy. The one, situated at Otranto, had no stamens; the other
at Brindisi, which is about forty miles distant, had no pistils; consequently, neither of those trees bore seed. But when, after the growth of many years, they not only rose superior to all the trees of the neighbouring forests, but overtopped all the buildings which intervened, the pollen of the palm-tree at Brindisi was wafted by the wind, to the pistils of that of Otranto; and, to the astonishment of every one, the latter bore fruit.
The seed, from which the future plant proceeds, is the sole end and aim of all the parts of fructification. It consists of several parts, the most essential of which is the embryo, or germen, called by Linnæus, corculum, whence the life and organization of the future plant originate.
The cotyledons, or seed lobes, are immediately attached to the embryo, of which they form, properly speaking, a part. They are commonly two in number, and, when the seed has sufficiently established its root, generally rise out of the ground, and form a kind of leaves. Hilum, the scar, is the point by which the seed is attached to its seed-vessel, or receptacle, and through which alone nourishment is imparted for the perfecting of its internal parts; it is also the point through which the radical is protruded in the first stage of germination.
There is no part of the vegetable kingdom, which offers so many striking proofs of admirable contrivance as the seed. The care, which Providence has bestowed upon it, is astonishing.
Independently of the innumerable means which are adopted for maturing and protecting the organs, on which the production of the seed depends, and which form part of the system of provision for perfecting it
independently, too, of the countless contrivances, some highly artificial, for the immediate purpose of perfecting it, the mode in which this organ is preserved after it is matured, evinces consummate care and wisdom. Sometimes it is packed up in a capsule, a vessel composed of tough and strong coats; sometimes, as in stone-fruits and nuts, it is closed in a strong shell, which again is enclosed in a pulp; sometimes, as in grapes and berries, it is plumped overhead in a glutinous syrup, contained within a skin or bladder; at other times, as in apples and pears, it is embedded in the heart of a firm fleshy substance; or as in strawberries, pricked into the surface of a soft pulp. These, and many other varieties, exist in what are called fruits. In pulse, and grain, and grasses ;-in trees, and shrubs and flowers, the variety of the seed-vessels is incomputable. We have the seeds, as in the pea-tribe, regularly disposed in parchment pods, which completely exclude the wet; the pod also, not seldom, as in the bean, lined with a fine down distended like a blown bladder; or we have the seed enveloped in wool, as in the cotton plant; lodged, as in pines, between the hard and compact scales of a cone; or barricadoed, as in the artichoke and thistle, with spikes and prickles; in mushrooms, placed under a penthouse; in ferns, within slits in the back part of the leaf; or, which is the most general organization of all, we find them covered by a strong close tunicle, and attached to the stem, according to an order appropriated to each plant, as is seen in several kinds of grain and of grasses.
Equally numerous and admirable are the contrivances for dispersing seeds. Who has not listened, in a calm and sunny day, to the crackling of furze-bushes, caused by the explosion of their little elastic pods, or watched the down of innumerable seeds floating on the summer breeze, till they are overtaken by a shower, which moistening their wings, stops their further flight, and at the same time accomplishes its final purpose, by immediately promoting the germination of each seed in the moist earth?
How little are children aware, as they blow away the
seeds of the dandelion, or stick burs in sport on each other's clothes, that they are fulfilling one of the great ends of nature.
The awns of grasses answer the same purpose.
Pulpy fruits serve quadrupeds and birds as food, while their seeds, often small, hard and indigestible, pass uninjured through the intestines, and are deposited, far from their original place of growth, in a condition perfectly fit for vegetation.
Even such seeds as are themselves eaten, like the various sorts of nuts, are hoarded up in the ground, and occasionally forgotten, or carried to a distance, and in part only devoured.
The ocean itself serves to waft the larger kind of seeds from their native soil to far distant shores. M'CULLOCH'S Course of Reading.
Living bodies are usually divided into the animal and vegetable kingdoms. It may seem at first sufficiently easy to make the distinction between an animal and a plant; and, as long as we confine our views to the higher orders of animated beings, there is no room for doubt. But when we descend in the scale to the radiated animals, which present no distinct nervous system, no organs of sensation, no observable mode of communication with the external world; it then becomes necessary to enquire more accurately into the peculiar points, which should decide us to arrange them under the one class, or the other. Perhaps the most certain of these, is the presence of a digestive organ. Cuvier mentions three other marks of distinction, which however are by no means so general. They are, the presence of nitrogen, as one of the chemical components of all animal bodies; the existence of a circulation; and respiration. Nitrogen does exist in all animal bodies,