of a bundle of hairs without branches, plumose when each hair has other little hairs arranged along its sides, like the beards on a feather.

In Fig. 112, a, re

presents the capil

lary, or hair-like

egret; b, is a pedi

celled egret; c and

forming a plumose train, as in the virgin's bower and

Geum; e, a wing, as may be seen in the fir; f, a sessile egret.

The number of seeds in plants is variable; some have but one; some, like the umbelliferous plants, have two; some have four. The number varies from these to thousands. A stalk of Indian corn is said to have produced, in one season, two thousand seeds. A sunflower four thousand. A capsule of the poppy has been found to contain eight thousand seeds. It has been calculated that a single thistle seed will produce, at the first crop, twenty-four thousand, and at the second crop, at this rate, five hundred and seventy-six millions. In the same species of plants the number of seeds is often found to vary. The apple, and many other fruits, might be given as examples. Seeds, according as they vary in size, have been divided into four kinds; large, from the size of a walnut to that of the cocoa-nut; middle size, neither larger than a hazel nut, nor smaller than a millet seed; small, between the size of the seeds of a poppy and a bell- . flower; minute, like dust or powder, as in the ferns and mosses.

When a pericarp separates itself from the parent plant, or when the valves of the fruit open, the fruit has ceased to vegetate; like the leaves at the end of autumn, it has lost its vital principle, and becomes subject to the laws which govern inorganized matter.

The maturity of the seed marks the close of the life of annual plants, and the suspension of vegetation in woody and perennial ones. Nature, in favouring by various means the dispersion of these seeds, presents phenomena worthy of our admiration, and these means are as varied as the species of seeds which are spread over the surface of the earth.

The air, winds, rivers, seas, and animals, transport seeds and disperse them in every direction. Those which are provided with feathery crowns, or egrets, as the dandelion and thistle, or with wings, as the maple and ash, are raised into the air and even carried across the seas. Linnæus asserted that the ERIGERON canadense was introduced into Europe from America, by seeds wafted across the Atlantic Ocean. "The seeds," says he, "embark upon the rivers which descend from the highest mountains of Lapland, and arrive at the middle of the plains, and the coasts of the seas. The ocean has thrown, even upon the coasts of Norway, the nuts of the mahogany, and the fruit of the cocoanut-tree, borne on its waves from the far distant, tropical regions; and this wonderful voyage has been performed without injury to the vital energy of the seeds."

Number of the seeds variable-Size variable-Separation of the pericarp from the plant-What is denoted by the maturity of the seed ?-Dispersion of seeds, how effected?-Seeds carried by water.

Some fruits, endowed with elasticity, throw their seeds to a considerable distance. In the oat, and in the greater number of ferns, this elasticity is in the calyx. In the Impatiens, wild cucumber, and many other plants, it resides in the capsule. The pericarp of the IMPATIENS* upon being touched, when the seeds are ripe, suddenly folds itself in a spiral form, and, by means of its elastic property, throws out its seeds.

Animals perform their part in this economy of nature. Squirrels carry nuts into holes in the earth. The Indians had a tradition, that these animals planted all the timber of the country. Animals also contribute to the distribution of seeds by conveying them in their wool, fur, or feathers.

Although distance, chains of mountains, rivers, and even seas, do not present obstacles sufficient to prevent the dispersion of plants, climate forms an eternal barrier which they cannot pass. It is not unlikely, that in future times the greater part of vegetable tribes which grow between the same parallels of latitude, may be common to the countries lying between them; this may be the result of the industry of man, aided by the efficient means which nature takes to promote the same object in the dissemination of seeds; but no human power can ever cause to grow within the polar circles, the vegetables of the tropics, or those of the poles at the equator. Nature is here stronger than art. That something may be done to promote the growth of tropical plants in our climate is true, but how different are they with us, from the same species in their own genial climate; we toil and watch for years to nurture an orange or lemon tree, which after all is stinted in its growth, while in its own native home the same plant would have grown spontaneously in luxuriant beauty.

The diffusion of seeds completes the circles of vegetation, and closes the scene of vegetable life. The shrubs and trees are despoiled of their foliage, the withered herbs decompose, and restore to the earth the elements which they have drawn from its bosom. The earth, stripped of its beauty, seems sinking into old age;—but, although the processes of nature may have been unseen and unmarked by man, innumerable germs have been formed, which wait but the favourable warmth to decorate with new brilliancy this terrestrial scene.

So fruitful is nature, that a surface a thousand times more extended than that of our globe, would not be sufficient for the vegetables which the seeds of one single year would produce, if all should be developed; but great quantities are eaten by men and animals, or left to perish in unfavourable situations. Some are carried into the clefts of rocks, or buried beneath the ruins of vegetables; here, protected from the cold, they remain inactive during the winter season, and germinate as soon as the early warmth of spring is felt. Then the pious botanist, beholding the vegetable species with which the earth begins to be clothed, and seeing successively all the types or representations of past generations of plants, admires the power of the Author of nature, and the immutability of His laws.

In concluding our examination of the external organs of plants, we will give a synoposis of the principal ones, with their subdivisions, as heretofore explained.

* The IMPATIENS of the garden is sometimes called Ladies'-slipper, sometimes Bal·

samine.

Elasticity of some fruits-Agency of animals-Effect of climate upon the dispersion of plants-Circle of vegetation completed-Concluding remarks.

PHYSIOLOGICAL VIEWS-GERMINATION OF THE SEED.

We have traced the various organs of the plant, through their successive stages of development, from the root to the bud, leaf, and flower, and from the flower to the fruit and seed. We have seen, in imagination, the vegetable world fading under a change of temperature, the "sear and yellow leaf" becoming a prey to the autumnal blasts, and even the fruits themselves exhibiting a mass of decayed matter. Were this appearance of decay and death now presented to us for the first time, how gloomy would be the prospect! How little should we expect the return of life, and beauty, and fragrance! No power short of Omnipotence, could effect this; it is indeed a miracle! But we are so accustomed to these changes, that, "seeing, we perceive not;" we think not of the mighty Being who produces them; we call them the operations of nature; but what is

Enumerate the organs of nutrition-Of reproduction-What are the parts of the root?-The Stem-Bud-Leaf-Different kinds of Appendages-Divisions of the calyx-Corolla-Nectary-Stamens-Pistil-What are the parts of the fruit?-What are the parts of the pericarp ?-Parts of the seed-Of the Embryo-What remarks commence this lecture?

nature, or the laws of nature, other than manifestations of Almighty power?

The word nature, in its original sense, signifies born, or produced; -let us then look on nature as a created thing, and beware of yielding that homage to the creature which is due to the Creator. The skeptic may talk with seeming rapture of the beauties of nature, but cold and insensible must be that heart, which, from the contemplation of the earth around, and the heavens above, soars not to Him, The mighty Power from whom these wonders are."

How impressively is the reanimation of the vegetable world urged by St. Paul, as an argument to prove the resurrection from the dead! The same power, which from a dry, and apparently dead seed, can bring forth a fresh and beautiful plant; can assuredly, from the ruins of our mortal frame, produce a new and glorious body, and unite it to the immortal spirit by ties never to be separated.

Leaving the external appearances of the plant, we are now to enter the inner temple of nature, and to examine into those wonderful operations by which vegetable life is called into action and sustained. Germination. The process of the shooting forth of the seed is termed germination. The principle of life contained in the seed does not usually become active, until the seed is placed in circumstances favourable to vegetation. When committed to the bosom of the earth, its various parts soon begin to dilate, by absorbing moisture. Chemical action then commences; oxygen from the air unites to the carbon of the seed, and carries it off in the form of carbonic acid gas. As the carbon of the cotyledons, by this process, continues to diminish, and oxygen is produced in excess, a sweet sugar-like substance is formed; this being conveyed to the embryo, it is by its new nourishment kindled into active life; from this period, we may date the existence of the young plant.

Fig 113.

Bursting through the coats which surrounded it, and which are already enfeebled by their loss of carbon, the embryo emerges from its prison; the radicle shoots downward, and the plume rises upward. We then say, the seed has come up, or sprouted. Fig. 113 represents a young dicotyledonous plant, with its radicle, a, developed; its plume, b, is yet scarcely perceptible; its cotyledons, c, appear in the form of large, succulent seed-leaves.

The radicle, or descending part, is usually the first to break through the coats of the seeds; it commences its journey downward, to seek in the soil nourishment for the future plant, and to fix it firmly in the earth. It always takes a downward course, in whatever situation

Meaning of the word nature-Feelings which should be excited by created objectsSt. Paul's argument for the resurrection-Describe the process of germination-Describe Fig. 113-Which part of the embryo first escapes from its integuments?

the seed may have been placed in the ground. A botanist once planted in a pot, six acorns, with the points of their embryos upward. At the end of two months, upon removing the earth, he found that all the radicles had made an angle, in order to reach downward. It is supposed that if the root met with no obstruction in going downward, it would always be perfectly straight.

Fig. 114.

Fig. 114 is a representation of a germinating seed of the Mirabilis, (four o'clock;) it will be seen that the radicle, a, has made nearly a right angle in turning downward; the plume is not developed.

a If you put cotton into a tumbler of water, and place upon it some seeds of rye or wheat, you will see all the fibres shooting from the seeds, in a perpendicular direction, downward. It is a very simple and interesting experiment. Some ascribe this phenomenon to the laws of gravitation, by which the root is attracted towards the centre of the earth; others say that the radicle, stimulated by moisture, extends itself in the natural direction from which it proceeds; while some imagine that the plant is endowed with a kind of instinct, similar to that which appears in animals from their first moments of existence, leading the little duck to seek the water, and the young bird to fly. Let us call this power by what name we will, or refer it to whatever secondary laws, we must ultimately attribute it to the will and design of Him who gave the plant its living principle.

After the young root has made some progress, the cotyledons swell, and rising out of the ground, form two green leaves, called seed-leaves. When the plume develops its leaves, these seed-leaves being no longer needed wither and decay.

You will recollect that the embryo or germ is composed of two principal parts, the radicle and plume. The radicle, we have just seen, extends itself downward. Soon after this part of the germ has begun its downward course, the plume, (so called from its resembling a little feather,) rises upwards, and soon becomes a tuft of young leaves, with which the stem, if there be one, ascends.

"Some rye being planted in a good soil, at the end of the second day its radicle was discernible. At the end of twenty-four hours the embryo had escaped from its integument. On the second day the fibres of the root had augmented, but the leaves had not appeared. On the fourth day the first leaf began to appear above the ground, at which time the colour was red. On the fifth day, it had grown to the length of an inch, and its colour was now green, and on the sixth day the second leaf had appeared."*

Rye belongs to that class of plants whose seeds have but one cotyledon, and this never rises above the ground to form a seedleaf. Seeds with but one cotyledon are chiefly composed of albumen, which performs the same office of nourishing the embryo during its germination, as the cotyledons of dicotyledonous plants. In some monocotyledons is perceived under the albumen, a part called vitellus, or the yolk; this, like the albumen, is entirely converted into nourishment for the young plant; it may be seen in the seeds of grasses, and is conspicuous in the Indian corn.

* Sumner.

Describe the experiment with acorns.-Describe Fig. 114-Causes assigned for the downward course of the radicle-Seed leaves-Plume-Experiment with rye-Seeds with one cotyledon-Vitellus.