gen gas, under the influence of the solar rays, while animals absorb and retain it.(8) They require food, as we do, but their roots are their mouths. They have not, like quadrupeds, a particular stomach and hepatic system for its digestion; but, like some of the lower animals, they have a power of assimilating and converting what they take into their own substance, without these functions.(9) But all vegetables are fixed in their place of growth; they have no locomotive power. Where they are born, they live and die. This circunstance would alone make them a peculiar class of beings, if they had every other similitude to animal existences. They are living beings, but with no power of spontaneous movability from their first station of development.(10)

The seed contains the embryo plant in the little corculum, which all, on being carefully opened, display. It is familiarly called the heart of the walnut-the little figure at one end of all nuts and kernels. Vessels extend from this to the substance in which it lies, which has received the name of cotyledon. If this be single, as in the grasses and corn, it is a monocotyledon seed and plant;(11) if, as

(8) “It is agreed that, in the day time, plants imbibe from the atmosphere carbonic acid gas; that they decompose it, absorb the carbon as matter of nourishment which is added to the sap, and emit the oxygen. This same gas they absorb from water when it is separated from that fluid by the action of light..... In the dark, plants give out carbon and absorb oxygen." Smith, ib. 212, 13.

(9) "With respect to those minute and simply constructed animals, the polypes and the lower tribes of worms, their feelers, put forth into the water, seem scarcely different from roots seeking their food in the earth. Some of these may be turned inside out, like a glove, without any disturbance of their ordinary functions." Smith, ib. p. 3.

(10) The vegetables that swim and live in water unattached to any soil, and which are nourished by what they float in, do not move themselves. They only follow the impulse of the stream. Nor has the curious AIRPLANT of China more self-motivity from not being fixed to any earth, but living in and on the air and light. It has the same want of locomotivity. This singular vegetable has been thus mentioned:

"Epidendron, flos aeris, a plant indigenous in China, famous for the beauty of its flowers and the sweetness of its perfume. It lives only on air. The Chinese suspend it round the ceiling of their rooms. Prince Leopold obtained a branch three feet long. It had some hundreds of large scarlet and yellow flowers." Bull. Univ. 1829, p. 167.

(11) "There is a tribe of plants called monocotyledons, characterized by having only one lobe to the seed. To these belong the natural order of PALMS, which being the most lofty, and in some instances the most long lived of plants, have justly acquired the name of trees. Yet they are

in the larger herbs and trees, it consists of two lobes, they are called dicotyledons;(12) if no such are discernible at all, they are termed acotyledon plants,(13) which in some, and perhaps in most countries, are the most numerous.(14) All plants consist of two substances, vessels, and cellular tissue. In general language, what is not one, may be deemed the cther. But for the delineation of the various parts of their mechanical structure, I would refer you to the latest publications of our scientific botanists. I shall only notice their more remarkable properties, which illustrate the principles and purposes of their Creator.

Their growth and nutrition.—The seed of plants resembles the animal ovum or egg. The embryo in both is at one end, with vessels ramifying into the rest of the substance, and deriving from that its first nutriment. The access of a certain degree of heat is necessary to begin the activity and development into both; and when that occurs to the seed, in a proper soil and place, and with sufficient moisture, vegetation begins. The cotyledons swell and rise in the seminal leaves. The corculum lengthens downwards in the germ of the radicle, and its upper part ascends in the plumula. A nutritious matter passes from the seminal leaves to the radicle, which daily elongates.(15)

rather perennial herbaceous plants, having nothing in common with the growth of trees in general. The palms are formed of successive crowns of leaves which spring directly from the root. The common ORANGE LILY and 'WHITE LILY belong to the same natural family of monocotyledons. Their stems, though only of annual duration, are formed nearly on the same principle as a palm; and are really congeries of leaves rising one above another, and united by their bases into an apparent stem." Smith's Int. Bot. P. 59.

(12) M. Desfontaines has made an important discrimination: "Plants in which the bark, wood, and pith are distinct, spring from seeds with two lobes, or dicotyledons. Those, where these are blended, form the monocotyledons."

(13) "Some think that all acotyledon plants, as mushrooms, mosses, &c., are entirely composed of cellular tissue, without vessels; and that monocotyledons have the cellular and vascular systems blended together through the entire stem; while all the dicotyledons have the two systems so symmetrically arranged, that the bark, wood, and pith, are always distinguishable from each other." Edinb. Rev. No. 99, p. 154.

(14) Thus in Denmark "The cotyledon plants amount to 1,600, and the acotyledon ones to 3,200." Bull. Univ. 1830, p. 269.

(15) "We then see a white cylindrical body develop at this point, while the embryo of the plumula remains stationary. From the end of this white

The process of vegetation thus beginning from the cotyledons, steadily proceeds under its subsequent nourishment from the earth and air, until the perfect plant is formed.(16)

Nothing is more curious in nature than the persevering efforts made by the living principle in plants to force their radicle downwards; whatever efforts may be made to give it another direction, are constantly baffled by the growing power, which knows where its nutrition lies, and will go rightly to seek it. No animal can display a more persisting volition.(17) Yet when circumstances become such, that its food is not downwards, but upwards, it will then, and then only, rest in that inverted and ascending position.(18) Earth is not so essential to vegetable growth as moisture; for even trees will grow in water only.(19) Earth is but the bed in which the vegetable nutrition is body the radicle issues; and soon penetrating the earth, attracts the fluids which make its lymph." M. Feburier, Bull. Univ. 1830, p. 74.

(16) "This lymph, by mixing with the nutritive substance that descends from the seminal leaves, forms the sap, which ascends to the plumula. Thus, the seminal leaves may be deemed the upper points of the roots of the plant, with which they have a direct communication by the stalk which separates them. The radicle is fixed in a contrary sense to the leaves, because the bundles of fibres which produce it, and the lymph which makes its first nourishment, descend from the cotyledons." Feburier, ib.

(17) "The young root is the first part of the infant plant that comes forth; and by an unerring law of nature it is sent downwards to seek out nourishment, as well as to fix the plant in the ground. In whatever position seeds happen to lie in the earth, the root makes more or less of a curve, in order to shoot downwards. Mr. Hunter sowed a number of seeds in a basket of earth placed on an axis, by which their position was a little altered every day. After the basket had thus made two or three circumvolutions, the young roots were found to have formed as many turns, in attempting to attain their natural perpendicular direction." Smith. Introd. p. 95.

(18) Dr. Walker remarks, "The ascent of the plume and the descent of the radicle are surprising. It is not merely to ascend or descend, but the endeavor of the one is to get into the air, and of the other into the earth. For, if placed to the roof of a cave, or in an inverted flower-pot, then, as I have often seen, the radicle ascends and the plume descends, the one to the earth above it, the other to the air below it." Woodh. Lord Kames, v. 2. Ap. p. 64.

(19) Du Hamel reared in water plants of the horse-chesnut and almond to some considerable size, and an oak till it was eight years old; but they made less and less progress every year. Their roots were found to be in a very bad state, and they died. London, Encyc. Gard. 197..... "Plants, though vegetating merely in water, do yet augment the quantity of their carbon." Ib..... Plants seem to have a mysterious power of making carbon, which may account for their growing a while in water only.

best prepared and presented to the absorbing roots. This is now stated to be an oxyd of carbon, or humic acid, made by a chemical union with water, and which forms that humus or soil that most occasions or promotes vegetation.(20) Without this vegetable humus, and the humic acid which is found in it, plants will not grow, or soon decay.(21)

When the plant develops in the fitting soil, the roots nourish it from below, and the leaves above contribute also their auxiliary supplies.(22) Buds emerge in due time from the stem or branches, each of which may be considered as a new vegetable, growing from its parent, but living in unseparating union with it, yet only in close association, for it seeks its own independent nurture by its distinct, though strictly combined root.(23)

Plants with few and small leaves depend chiefly on the soil. Those with many and large ones, more on the atmosphere.(24) But some can find nutriment, and grow, even from animals. Thus cryptogamic plants have been

(20) Dr. Sprengel expresses this principle. His ideas are, that the humic acid and humates become the nutritive principles of plants; that they are formed at first from the soft parts of plants, and afterwards from the dissolution of their fibres; that in their decomposition, one part of their carbon combines with the oxygen of the air, and produces carbonic acid, which separates itself; and also the humic acid, which combines chemically with water, for which it has a great capacity, and is imbibed by plants. Bull. Univ. 1830, p. 205.

(21) "Heaths furnish a humus that suits few vegetables. Hence, vegetation is so uniform on their sterile plains. Plants cultivated on such grounds do not increase, unless we mix marl or dung. In nature, turf is that which contains the greatest quantity of humic acid." Dr. Sprengel, ib. p. 202.

(22) "If the air contain a certain quantity of humidity, the leaves attract a part of it; while they contribute to the elaboration of the plants peculiar fluids, which pass through the proper vessels of the bark and wood. The combination of these fluids with the sap of the leaves and that of the roots forms the cambium which penetrates between the wood and bark, and makes there the new woody substance; while the sap, descending to the extremity of the rad cle, contributes to elongate, and often to make new ramifications from it." Febur. Ib. That the leaves nourish the bark appears from Mr. Knight's experiments: when he reduced the number of leaves in a shoot, the bark became shriveled and dry. Phil. Trans. 1801. (23) M. Poiteau remarks, that "a tree or plant is not a simple individual. It is a union of universally independent plants, arising, each, from a bud. This bud may be considered as a seed, which produces latent roots that descend towards the earth, and. constitute the fibres of the wood." He shows that the woody fibres are the roots of the buds.

(24) Burnett, in Quart. Journ. Science, No. 12, p. 286.

found vegetating on living wasps in the West Indies.(25) This curious fact has been also noticed elsewhere.(26) They will even grow in the stomach of living animals; for several instances of this have occurred, in which the force of vegetation has prevailed over the animal's digestive power; at least in those who were entirely carnivorous.(27)

Warmth and moisture usually commence the process of germination as soon as they concur to the seed; but if the due means for the further nutriment do not accompany the growth, the process stops, and the plant soon dies.(28) Some vegetables-the parasitic tribes-fasten on a larger plant or tree, and fixing in them their roots, derive food from its nutritive juices.(29) The living principle exerts itself with singular force and apparent judgment in searching for its nutrition when the ordinary sources and supply of it fail.(30) The main fluid in vegetables is the sap.

(25) Mr. Ricord, in Gaudaloupe, saw many wasps laden with these parasitical excrescences, which had taken root on their sternum. Bull. Univ. 1829, p. 137.

(26) Dr. Madiana had thought that the plants sphæria, clavaria, and other mushrooms, which were found on the bodies of some insects, had grown there only since their death: but Dr. Mitchell ascertained—

I. That the vegetation observed on the bodies of insects is not peculiar to one kind, but was on several, as wasps, sphynx, and may-bugs.

II. That the bodies of insects nourish several kinds of plants, as spheria, clavaria, and some others.

III. And that some part of these vegetable parasites begin their destructive operations on the bodies of living animals, like the larvæ of ichneumon, and continue it until their death." Bull. Univ. 1829, p. 226.

(27) Thus of three gneiss pebbles taken out of a coD's stomach, on one a plant of the fucus kind, fucus confervoides, of a deep green, was found growing in active vegetation, and nearly two feet long;-on the other, a plant two thirds shorter than the former was growing; and another was attached to it about three inches long. The stones adhered strongly to the substance of the stomach, and were cut out from it. Quart. Jour. Scien. No. 10. p. 443.

(28) Smith's Introd. 99. Germination will sometimes begin without either earth or water. It was stated in the Med. Bot. Society, that Mr. Currie had inclosed some potatoes in a zinc box hermetically sealed, and from which all stimulants had been excluded, and yet they began to shoot freely there.

(29) Ib. 102.

(30) Dr. Walker mentioned to Sir J. Smith, that an ash tree which grew from a seed on a wall, stopped its growth for a while, having exhausted the nutriment there; but sent a root down the wall until it reached the ground, and as soon as this was established in the soil, the tree resumed its vegetation and became of large size. Smith's Introd. Bot. p. 114. And see Trans, Linn, Soc. v. 2. p. 268.