Go, mark the matchless workings of that Power In colour these, and those delight the smell Cowper. DISSEMINATION OF PLANTS.-When seeds are come to maturity, their dissemination is absolutely necessary, since without it no future crop would follow. The great Author of nature has wisely provided for this in various ways. The stems of many plants are long and slender, and being raised above the ground, the wind shakes them to and fro, and by this means are the ripe seeds conveyed to a distance. The seed-vessels of most plants are shut till the seeds are ripe, that so the winds may not scatter them prematurely; and when the proper season arrives, many of these open with such a degree of elasticity as to throw the seeds to a considerable distance. Other seeds have a kind of wings given them, by which they are conveyed to a distance of some miles from the parent plant. These wings consist either of a down, as in most of the composite-flowered plants, or of a membrane, as in the birch, alder, ash, elm, &c. Hence woods, which happen to be destroyed by fire, or any other accident, are soon restored again by new plants. Some seeds are rough, or provided with a sort of hooks, by means of which they are apt to stick to animals that pass by them, and by this means are carried to the mouths of their burrows, where they meet with proper soil and manure for their growth. Berries and other pericarpies are by nature allotted for aliment to animals; but it is on condition that they shall sow the seed while they eat it: this they do by dispersing the seeds as they are eating; and also after eating, by voiding many of them unhurt, and even in a better state for vegetation than they were before. Thus many kinds of nuts are sown; and thus did the doves of the Moluccas replant with nutmegs those islands of the East, which the sordid avarice of the Dutch had destroyed: Providence thereby frustrating, by feeble but certain means, the contemptible selfishness of that commercial people. In this manner the woods of northern countries are sown with junipers, by the thrushes and other birds which feed upon these heavy berries. The cross-bill lives upon fir-cones, and the hawfinch upon pine-cones; by means of which the fir and the pine, of various species, are continually planted in vast abundance. In our own country, the common rook has been observed, not only to feed on acorns, but to make holes in the ground with the bill, and hide many: probably they mean only to lay in a stock for future necessity by this process; Dut certain it is, that thousands of oaks are annually planted by this means. Swine, also, in searching for food, turn up the earth; and inoles, by throwing up hillocks, prepare the ground for seeds of various kinds. Seas, lakes, and rivers, by their streams and currents, often convey seeds unhurt to distant countries In assimilating the animal and vegetable kingdoms, Linnæus denominates seeds the eggs of plants. The fecundity of plants is frequently marvellous: from a single plant or stalk of Indian Turkey wheat, are produced, in one summer, 2000 seeds; of elecampane, 3000; of sun-flower, 4000; of poppy, 32,000; of a spike of cat's-tail, 10,000 and upwards: a single fruit or seed-vessel of tobacco, contains 1000 seeds; that of white poppy, 8000. Mr. Ray relates, from experiments made by himself, that 1012 tobacco seeds are equal in weight to one grain; and that the weight of the whole quantum of seeds in a single tobacco plant, is such as must, according to the above proportion, determine their number to be 360,000. The same author estimates the a...ual produce of a single stalk of s leen-wort to be upwards of 1,000,000 of seeds. quan PRODIGIOUS NUMBER OF PLANTS UPON THE EARTH.-It is said, that there are about 44,000 different plants already discovered, to which new ones are daily added. By means of the microscope, some have been found where they were least expected. The different varieties of mosses and sponges have been classed among vegetables, and have presented to the observation of the naturalist, seeds and flowers before unknown. Freestone is sometimes covered with brown and blackish spots; the mouldy substance which composes them adheres to various other matters, and may be considered as a little garden in vegetation. When we reflect upon the tity of moss which covers the hardest stones, the trunks of trees, and the most barren places;-when we consider the quantity of vegetables upon the surface of the earth; the different species of flowers which delight and refresh us; the trees and bushes, add to these the aquatic plants, some of which exceed a hair in fineness;-we may be able to form some idea of the multitude of plants in the vegetable kingdom. All these species grow up, and are preserved without detriment or injury, each having that place assigned it, which is most suited to its properties. Such is the wisdom displayed in their distribution over the surface of the earth, that there is no part of it wholly destitute, and no part enjoys them in too great abundance. Some plants require the open field, where, unsheltered by trees, they may receive the sun's rays; others can only exist in water; some grow in the sand, others in marshes and fens, which are frequently covered with water, and some bud on the surface of the earth, whilst others unfold themselves in its bosom. The different strata which compose the soil of the earth, as sand, clay, chalk, &c. favour different vegetables; and hence it is, that in the vast garden of nature nothing is absolutely sterile; from the finest sand to the flinty rock, from the torrid to the frozen zone, each soil and climate supports plants peculiar to itself. Another circumstance highly worthy of attention is: the Creator has so ordered, that, among this immense variety of plants, those which are most proper for food or medicine multiply in greater abundance than those which are of less utility. Herbs are much more numerous than trees and brambles; grass is in greater abundance than oaks; and cherry-trees more plentiful than apricots: had oaks been more frequent than grass, or trees than herbs and roots, it would have been impossible for animals to subsist. According to the calculation of Baron Von Humboldt, 6000 plants are agamous, that is, plants which have no sexual organs, such as champignons, lichens, &c. Of the remainder there are found 3,000 In the temperate regions of America, in both hemi spheres ... 4,000 In Equinoxial America. 13,000 Ir New Holland, and the Islands of the Pacific Ocean 5,000 SENSIBILITY OF PLANTS.-There are certain motions onservable in plants, that make it doubtful whether they are not possessed of sensibility. Some plants shrink and contract their leaves upon being touched; others open and shut their flowers at certain fixed hours in the day, so regularly as to denote with precision the time of day; some assume a peculiar form during the night, folding up their leaves; and these different changes take place whether .ney are in the open air, or shut up in close apartments. Those which live under water during the time of fecundation, raise their flowers above the surface. The motions of a marshy plant discovered some time since, in the province of Carolina, are still more singular. Its round leaves are furnished above, and on the sides, with a multitude of notches that are extremely irritable. When an insect happens to creep upon the sperior surface of the leaves, they fold up, and inclose the insect till it dies; the leaves then open of themselves. We may daily observe regular motions in some plants in our gardens. Tulips expand their petals when the weather is fine, and close them again at sun-set, or during rain. Vegetables with pods, such as peas and beans, open their shells when dry, and curl themselves up like shavings of wood. Wild oats, when placed upon a table, wil! move spontaneously, more especially if warmed in the hand And the heliotrope, or sunflower. with various other plants, always turns towards the sun. These are incontestable facts, of the certainty of which every person may be easily convinced From them, some conclude that we ought not to deny sensibility to be an attribute of plants; and certainly the facts which are alleged in favour of such an opinion, give it great appearance of probability. But, on the other hand, plants have no other sign of sensibility; and all that they have is entirely mechanical. We plant a shrub and destroy it, with out finding any analogy between it and an animal, that we bring up and kill. We see a plant bud, blossom, and bear seed, insensibly, as the hand of a watch runs round the points of the dial. The most exact anatomy of a plant does not unfold to us any organ which has the least relation to those of animal sensibility. When we oppose these observations to those from which we might infer the sensibility of plants, we remain in uncertainty, and we cannot explain the phenomena related above. Our knowledge upon this subject is very imperfect, and is confined to simple conjecture. We neither attribute sensibility to plants, nor deny it to them, with cer tainty. THE SENSITIVE PLANT.-This singular plant rises from a slender woody stalk seven or eight feet in height, armed with short recurved thorns; the leaves grow upon long footstalks, which are prickly, each sustaining two pair of wings; from the place where these are inserted, come out small branches, having three or four globular heads of pale purplish flowers coming out from the side, on short peduncles; the principal stalk has many of those heads of flowers on the upper part, for more than a foot in length; this, as also the branches, is terminated by like heads of flowers; the leaves move but slowly when touched, but the footstalks fall, when they are pressed pretty hard. It is a native of Brazil, (M. pudica, humble plant,) having the roots composed of many hairy fibres, which mat slowly together; from these come out several woody stalks, declining towards the ground, unless supported; they are armed with short recurved spines, having winged or pinnate leaves; flowers from the axils, on short peduncles, collected in small globular heads, of a yellow colour. ЗА 66 Naturalists (says Dr. Darwin) have not explained the immediate cause of the collapsing of the sensitive plant; the leaves meet and close in the night, during the sleep of the plant, or when exposed to much cold in the day-time, in the same manner as when they are affected by external violence, folding their upper surfaces together, and in part over each other like scales or tiles, so as to expose as little of the upper surface as may be to the air, but do not, indeed, collapse quite so far; for when touched in the night during their sleep, they fall still further, especially when touched on the footstalks between the stems and the leaflets, which seem to be their most sensitive or irritable part. Now, as their situation after being exposed to external violence resembles their sleep, but with a greater degree of collapsion, may it not be owing to a numbness or paralysis consequent to too violent irritation, like the pantings of animals from pain or fatigue? A sensitive plant being kept in a dark room till some hours after day-break, its leaves and leaf-stalks were collapsed as in its most profound sleep, and on exposing it to the light, above twenty minutes passed before the plant was thoroughly awake, and had quite expanded itself. During this night the upper surfaces of the leaves were oppressed; this would seem to shew that the office of this surface of the leaf was to expo ? the fluids of the plant to the light, as well as to the r." Dr Darwin has thus characterized these plants.— Weak with nice sense the chaste Mimosa stands, 10 |