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single year. It is always fibrous or composed of numerous branches or rootlets. Biennial roots are those of plants which do not blossom till the second year, at the end of which they perish. They are thickened or fleshy, and of various shapes—conical, as in the carrot; spindleshaped, as in the radish ; turnip-shaped, clustered, tuberous, etc. Perennial roots are those which, like the roots of trees and woody plants, and some others, survive from year to year indefinitely.
A tuber, of which the potato is the best example, is not strictly a root, but a modification of the stem, running beneath the surface of the soil, and having buds (eyes) embedded in a cellular substance, consisting principally of starch.
Bulbs, whether formed in the earth, as is generally the case, or on the summit of the stem, as in the top or tree onion, are simply leafbuds inclosed in scales or concentric layers.
III. -THE STEM.
As soon as the root enters upon the performance of its proper function, the stem begins to extend itself upward, and the primary leaf-bud, attracting to itself the food procured for it, and a part of the nutritive matter stored up in the seed-leaves, expands, and the two or more parts or leaves of which it is composed separate, and begin to manifest their distinctive features.
The stem is at first composed entirely of cellular tissue, possessing neither strength nor tenacity ; but at the moment that the first rudiment of a leaf appears upon its growing point, the formation of woody matter commences. It consists of tough fibres of extreme fineness, which take their rise in the leaves, and thence pass downward through the cellular tisue and are incorporated with the latter giving it the necessary strength and flexibility. In trees and shrubs these fibers combine intimately with each other, and form what is properly called wood; but in herbaceous and annual plants they constitute a lax fibrous matter. The woody matter thus plunged, as it were, into the cellular tissue, forms within the circumference of the stem a tubular partition, separating it into two parts—the bark and the pith. This gives us, in perennial stems, the three general divisions of pith, wood, and bark.
The pith consists entirely of cellular tissue, gorged at first with the nourishing juices of the plant, but afterward becoming empty and dry.
The wood consists of the proper woody fiber, interwoven with and bound together by thin plates or layers of cellular tissue, passing horizontally across it, and forming what are called the silver grain in maple, oak, etc. They represent the horizontal system of the woodin botanical language, medullary rays.
The bark consists originally of cellular tissue alone, but afterward the inner portion next the wood has the woody tissue formed in it, and becomes the liber, or fibrous inner bark.
Whenever a stem is wounded, it is the cellular or horizontal system which forms granulations that eventually coalesce into masses, within which the woody tissue is subseqently developed, and the communication between the two sides of an incision effected. In cuttings, the callus which forms at the end placed in the ground is the cellular or horizontal system preparing for the woody fibers, which are to pass downward in the form of roots.
The description we have given of the structure of a stem applies to all plants whose woody matter is augmented annually by external additions below the liber, and which are called exogens, or outside growers. All the trees and shrubs of the United States, except the few palms of our Southern! confines, belong to this class.
In the palms, which belong to the class of endogens, or inside growers, the woody matter is augmented annually by internal additions to their center, thus constantly pushing the woody growth of former years to their circumference. The stem of the asparagus exhibits a similar structure in an herb. In endogens, the cellular and fibrous systems are all mixed together, their mode of growth not requiring the same arrangement of parts as exists in the oxogens.
Stems, during their growth, form on their surfaces minute vital points, each of which becomes, or may become, a leaf-bud, capable of forming another stem or branch like that on which it is found. These buds appear immediately above the point of union between the leaf and the stem, and are not, under ordinary circumstances, found anywhere else. They occasionally, however, appear on other parts, when they are called (as when found on the roots) adventitious buds. It is by means of the leaf-buds that a cutting is capable of producing a new individual like that from which it was taken. Leaf-buds are also capable, under fitting circumstances, of growing when separated from the parent branch. In some cases they are planted in the earth, when they put forth roots, and thereby sustain an independent existence. In others they are inserted below the bark of a kindred species, and, forming new wood, adhere to that on which they are placed.
The principal functions of the stem (aside from its continual multiplication of itself by means of buds) are the support of the leaves and the conveyance and distribution of the sap. In trees, the sap or crude food procured by the roots rises principally through the newer wood; but the assimilated sap returns from the leaves in the newest bark, or liber, whence it is horizontally diffused, through the medullary rays, into the sap-wood and other living parts. It is in the bark, therefore, and not in the wood, that we must look for the proper juices of a plant.
A leaf, as defined by Dr. Lindley, is an appendage of the stem of a plant having one or more leaf-buds in its axil, or point of union with the stem. In some cases no leaf-buds are visible, but they are present, nevertheless, although latent, and may be developed by favorable conditions.
A complete leaf consists of the lamina, or blade, and the petiole, or leaf-stalk In some leaves the petiole is wanting, the lamina resting immediately upon the stem, and in others there is no proper blade, the whole organ being cylindrical or stalk-like.
Considered in reference to their structure, it may be said leaves are extensions of the green layer of the bark (which, where no proper leaves exist, fulfills their function) expended into thin lamina and strengthened by woody fibers connected with the liber or inner bark, and with the wood. These woody fibers form their frame-work, and afford, at the same time, by their microscopic ramifications, a complete and beautiful system of veins. The leaf, therefore, like the stem, consists of two distinct parts, the cellular and the woody. The cellular portion is not the structureless, pulpy mass which it appears to be to ibe naked eye, but presents a regular and beautiful arrangement of cells. The woody part forming the veins, and baving, as we have seen, a double origin, is arranged in two layers; the upper, arising from the wood, and conveying the ascending sap to every part of the leaf, and the lower, connected with the liber and establishing a communication with the bark, by means of which the assimilated juices pass downward. Encasing the whole of this wonderfully beautiful apparatus is the epidermis, or skin pierced by numerous invisible pores or holes, called stomates, through which the plant breathes and perspires.
It would be interesting in connection with the foregoing brief outline of the structure of the leaf, to give some account of the different forms of leaves, their various modifications, and their systematic and beautiful arrangement on the stem; but as the practical ends we have in view do not require us to pursue ihe subject further in this direction, we must forego it.
Leaves have been called the lungs of plants. They are something more than this, being not only orga.s of respiration, but of perspiration and digestion also. They are, at the same time, stomach, lungs, and skin. They receive the crude sap from the roots through the stem, and by means of exposure to air and light, the decomposition of water, and carbonic acid, and the throwing off of superfluous moisture, condense it and change it into organizable matter—the true food of plauts. This elaborated sap is sent immediately downward, to serve for the nourishment of every part.
The nutrition of a plant depending upon its leaves, the former may be destroyed by simply destroying its foliage In general, it does not immediately die, because it has the power of putting forth new leaves, which come into action and supply imperfectly the places of those removed ; but if it be deprived of these essential organs during the entire season, its power of producing them ceases and all funetions are suspended.
V.-FLOWERS AND FRCIT.
A flower is that part of a plant which is formed for the purpose of reproducing its species by means of seeds. Fruit is the seed, or the seed and its pericarp, or covering. The pericarp includes whatever goes to make up the seed-vessel, whetber it bea were thin husk, a hard, bone-like shell, or a soft, flesky pulp.
Anatomically considered, the parts of a fower are merely modified leaves, the whole forming a very short branch. What causes a plant 10 convert some of its leaf-buds into flowers, by fashioning the leaves into calyx, corolla, stamens, and pistils, while other buds become ordinary branches, it is not essential to our purpose to explain. It is pretty clear, however, that their production depends upon the presence in the plant of a sufficient quantity of secreted maller, fit for their maintenance when produced. If it happen, then, that, from any cause, there be not, at the usual time of flowering, any store of nutritive juices beyond wbat is required for the production of leaves and the growth of the stem, no flower buds are put forth. This is illustrated in the failure of fruit trees to bear at all the season next succeeding one in which an excessive crop has been produced. Sometimes flowers are produced, but the supply of nutriment proving insufficient, they drop off without producing fruit.
Lindley syllogistically says: "A flower being a kind of branch, as has been already shown, and the fruit being an advanced stage of the flower, it follows that a fruit is also a kind of branch.” It has certainly the same organic connection with the plant as other branches, and, like them, requires to be supplied with food, without which it must perish.
So long as a fruit retains its original green, foliaceous character, it is capable of performing, partially at least, the functions of a leaf, decomposing carbonic acid, etc. A portion of the food required for its maturation may therefore be derived, by its own action from the air ; but the greater part must be prepared by the leaves from material furnished by the roots. This shows the necessity of the healthy and regular action of the leaves and roots in perfecting fruit, and the importance of fruit being placed near the leaves, so that it can readily attract the required nutriment from them. If you remove all the leaves from a branch containing fruit, you stop the growth of the latter almost as effectually as by separating it from the stem.
The juices furnished by the leaves undergo further alterations by the vital forces of the fruit itself, and this alteration varies according to the species. The fruit of the peach is sweet, but there is no perceptible sweetness in its leaves ; and the fruit of the fig is sweet and nutritious while the leaves of the plant are acrid and deleterious.
Among the principal immediate causes of the changes which occur in the secretions of fruits are beat and light. Fruits produced in warm seasons are always much sweeter than those which are matured in cold ones; and the products of hot climates abouod in sugar, while in those of cold climates acidity prevails.
The ripening of fruit is bastened by dryness, and retarded by an excess of moisture.
Seeds are affected by all the circumstances which affect the fruit, which is created primarily for their nutrition and preservation. The fruit attracts organizable matter from the leaves, and the seeds attract it from the fruit. The better the fruit, therefore, the more perfect are the seeds.
All seeds will not equally produce vigorous plants; but the healthi. ness of the seedling will correspond with that of the seed from which it sprung. Where vigor is required, the plumpest and beaviest seeds should be selected.
A seed always produces a plant of the same species as that from which it was derived, but is not certain to reproduce any peculiarity that may have existed in iis parent. For instance, the seed of a Green Gage plum will grow into a new individual of the plum species, but it is not certain, or even likely, to produce the variety known as the Green Gage. The variety must be propagated in some
FERTILITY OF THE HOLY
No country of equal size probably contains greater inequalities of surface than Palestine-varying from the peaks of Lebanon, ten thousand feet above the sea level, to the plain of Jericho, one thousand three hundred feet below it. Hence the Holy Land afforded almost every variety of vegetable productions; and when in its glory, populous and cultivated, and enjoying the smiles of Jehovah, it was not unworthy of the glowing rhapsody of Dr. Hamilton, the emphatic terms of which are almost all from the Bible :
“A better country than this, earth did not contain. It was 'a delightsome' and 'a pleasant land; a goodly heritage of the hosts of nations. It was variegated and intersected with all the elements of sublimity and beauty, with whatever was bold and gentle. It was a wealthy place. Aromatic herbs covered its hills, and the fairest flowers decked its glens. The rose was in Sharon, and the lily in the valleys. The voice of the turtle was heard in the land. There roamed the vine, and there clustered the date, and there hung the pomegranate. The cedar towered on the mountains, and the myrtle skirted their sides. No human hand could raise the clusters of Eshcol. The south wind, passing over the gardens, caused the spices thereof to flow out. The seasons revolved in their variety, but with a blended sweetness. There was the upland breeze, in which the fir could wave its arms, and the softer air, in which the olive unfolded its blossom. The sun smote not by day, nor the moon by night. The birds sang among the branches. The dew lay thick in Hermon. There was balm in Gilead. The lign aloe drooped from the river bank. Lakes glistened in the landscape, and cooled the drought. Beautiful for situation was Mount Zion. The cattle browsed on a thousand bills. The excellency of Carmel and the glory of Lebanon set their pinacles against the deep azure of Canaan's sky. The year was crowned with goodness. The Lord God cared for that land, and his eye was always upon it. At the stated period fell the earlier and latter rain. The pastures were clothed with flocks. The ploughman overtook the reaper; and the treader of grapes him that sowed the seed. The barns were filled with plenty, and the presses burst out with new wine. The little hills rejoiced on every side. The vineyards distilled the pure blood of the grape. The fountain of Jacob was upon a land of corn and wine. The inhabitants were filled with the finest of the wheat. It flowed with milk and honey. Its heavens dropped fatness. The land might be called Beulah. The distant glimpse of its prospect refreshed the dying eye of Moses; and of all thine earthly territory this is emphatically thy land, O Immanuel.”
MERIT AND PLACE.
A jewel is a jewel still, though lying in the lust,