The horseradish-tree of the West Indies - Moringa - attains the height of twenty-four feet in nine months, and that in a stony, poor soiL The power of vegetation within the tropics, is illustrated by the above as well as by the growth of the bamboo, which sometimes shoots fourteen inohes in the course of twenty-four hours. The extraordinary productiveness of the tropics, is by many considered an inestimable advantage, but the counterbalancing evil is the astonishing growth of the weeds. The poet may sing .

"Of the redundant growth Of vines and maize, and bower, and brake, Which nature, kind to sloth, And scarce solicited by human toil, Poors from the riches of the teeming soil," but the planter finds that nowhere is more care and industry required than within the tropics, to make agrioulture profitable. The weeds exhaust and smother everything that is not frequently attended to. - Why is it? Our government land costs one dollar an acre on an average, and champagne two dollars a bottle. How many a man dies landless, who, during his life, has swallowed a township - trees and all. - Captain Pope, who was in command of the expedition to dig artesian wells in Texas, reports a novel source of fuel, in the roots of the mesquit, which are found preserved beneath the soil - perfectly sound and hard - extending sometimes to the incredible depth of seventy feet! - The sales of the land on draining the Lake of Haarlem, produced sufficient money to repay all the expenses incurred. Sixteen years of labor and care were exhausted before the work was completed. As soon as the grounds were dry, they were covered spontaneously with a multitude of plants, reeds, and willows; these prevented walking, being soon higher than a man.

A heavy roller was passed over the brittle plants after the willows are pulled up, and the fallen stems covered with the earth taken from the ditches, and rape-seed was immediately sown; the rape overpowers the next growth, and the land is then ready for grain. After harvest, they work with large wooden shoes on the horses' feet, when the soil is yet too soft. If the horses sink, they leave them on the spot.- - Though the Berberries are commonly treated as shrubs, some of them may be formed into the most beautiful and durable small trees that can be introduced into gardenesque scenery. The common berberry, when pruned up to a single stem to the height of eight or ten feet, and all suckers from the root, and all side buds from the stem removed at the moment they appear, will form a fine .orbicular head, with the extremity of the branches drooping; and this pendulous appearance will increase with the age of the tree. Such a tree, covered, as it will be, every year, with yellow blossoms and scarlet fruit, may rank, in beauty and value, with the handsomest. The low-growing berberries - now mahonias - are very beautiful in masses. The common berberry, trained as above, will reach the height of thirty feet, and endure for centuries.

In a catalogue for 1825, the now common Mahonia aquifolium is priced at twenty-five dollars! - The best plan to forward cut flowers to a distance without injury, is to prepare a cylinder of tin three or four foot in length, and eight or nine inches in diameter. In the centre of this, place a tin tnbe, of, an inch in diameter, which fits into sockets in the bottom and the lid. Bound this tnbe the flowers are tied, and it is inserted in the bottom; the centre tnbe is now filled with water, and corked, and the lid pnt on, in which is the socket which embraces the tnbe. The case may now be sent to any distance, the natural moisture and the water keeping the flowers cool and fresh. A little damp moss, tied under the flowers, will assist this.