Figuier.

Commit a seed to the earth; plant, for example, a Lima bean, at the depth of two inches in moist vegetable soil. The seed will not be slow to germinate; first swelling, and then bursting its outer skin, a vegetable in miniature will, after a time, slowly reveal itself to the observer. In the meantime two very distinct parts make their appearance; one, yellowish in color, already throwing out slender fibrous shoots, sinks farther into the soil,—this is the radicle, or root; the other of a pale greenish color, takes the opposite direction, ascends to the surface, and rises above the ground,—this is the stem.

This root and stem are the essential organs of vegetation, without which, when we have excepted certain vegetables of an inferior order, plants adorned with leaves and flowers cannot exist. How vast the difference between the verdant top of a tree, which rises graceful and elegant into mid-air,—not to speak of the flower it bears—and the coarse, tangled mass of its roots and rootlets, without harmony, without symmetry! These organs, so little favored in their appearance, have, however, very important functions in the order of vegetable action.

The chief offices of the root are two: in the first place, it attaches the plant to the soil, holds it in its place, and prevents it from being overwhelmed by the elements. In the second, it feeds the plant by absorbing from the earth the sap necessary to its growth. How is this done?

The root branches again and again as it grows, throwing out numerous smaller branches. These hollow, thread-like rootlets suck up, from the soil, the water and other things, which are to go, through the stem or trunk and the branches, to all the leaves. Here these are made into the perfect sap, which, being distributed, causes the plant to grow, to blossom, and to bear fruit.

The manner in which roots succeed in overcoming obstacles, has always been a subject of surprise to the observer. The roots of trees and shrubs, when cramped or hindered in their progress, have been observed to exhibit considerable mechanical force, throwing down walls or splitting rocks; in other cases, clinging together in bunches, or spreading out their fibres over a prodigious space, in order to follow the course of a rivulet with its friendly moisture.

A celebrated botanist of the last century relates that, wishing to preserve a field of rich soil from the roots of a row of elms, which would soon have exhausted it, he had a ditch dug between the field and the trees in order to cut the roots off from it. But he saw with surprise that those roots, which had not been severed in the operation, had made their way down the slope so as to avoid meeting the light, had passed under the ditch, and were again spreading themselves over the field.

There are some roots which are developed along the stem itself. These supplementary organs come as helps to the roots properly so called, and replace them when by any cause they have been destroyed. In the primrose, for example, both the principal and the secondary roots springing from it, perish after some years of growth, but the supplementary roots, springing from the lower part of the stalk, prevent the plant from dying.

In the tropical forests of America and Asia, the vanilla, whose fruit is so sought after for its sweet aroma, twines its slender stem round the neighboring trees, forming an elegant, flexible, and aerial garland, an ornament in these vast solitudes, at once grateful and pleasing. The underground roots of the vanilla would not be sufficient for the nutriment of the plant, and the rising of the nourishing sap would take place too slowly. But Nature makes up for this inconvenience by the air roots which the plant throws out at intervals along its stem. Living in the warm and humid atmosphere of tropical forests, the stronger shoots soon reach the ground and root themselves in the soil. Others float freely in the atmosphere, inhaling the moisture and conveying it to the parent stem.

A grand tree—the banyan, or the pagoda fig-tree—adorns the landscape of India, and presents the most remarkable development of aerial roots. When the parent stem has attained the height of some fifty or sixty feet, it throws out side branches in every direction, and each branch in its turn throws out supplementary roots, which descend perpendicularly in long slender shoots till they reach the ground. When they have rooted themselves in the soil, they increase rapidly in diameter, and soon form around the parent stem thousands of columns, each throwing out new lateral branches and new roots.

The natives love to build their temples in the intervals left between these roots of the wild fig-tree. A famous banyan tree on the Nerbuddah is said by Professor Forbes to have three hundred large and three thousand smaller aerial roots; it is capable of sheltering thousands of men, and thus forms one of the marvels of the vegetable world; it is, in short, a forest within a forest.

Roots constantly endeavor to bury themselves in the earth. They seem to shun the light of day; and this tendency is to be seen from the very first moment when the root shows itself in the seed. The tendency is so decided, and appears so inherent in the life of all vegetables, that if we reverse a germinating seed, placing it with the root upwards, the root and the stem will twist round of themselves,—the stem will stretch upward, and the root will bury itself in the ground.