Many favorable circumstances are essential to this end. And at first the soil must be neither too light nor too meagre: otherwise, the roots lacking depth and grasp, the tree would fall at the first gale of wind. Next, the soil must not be too dry; otherwise the tree will wither where it stands deprived of the moisture of springs and streams. Moreover, the climate must be warm; or the tree, which is delicate, will freeze, or at least droop, and never put forth sprouts; the summer must be long, in order that the fruit, which is slow in ripening, may fully mature; and the winter mild, so that January frosts may not blast or shrivel the oranges that remain green on its branches. Finally, the soil must not be too favorable for other plants, lest the tree, left to itself, might be stifled by the competition and infringement of a more vigorous vegetation. When all these conditions concur, the little orange will grow, become mature, and produce others again to reproduce themselves. Storms will undoubtedly occur, stones fall, and browsing goats will destroy certain plants; but on the whole, in spite of accidents which kill individuals, the species will be propagated, cover the ground, and in a few years display a nourishing grove of orange trees. All this is to be seen in the admirably sheltered gorges of Southern Italy, in the environs of Sorrento and Amain, on the shores of the gulfs, and in the small, watered valleys, freshened by streams descending from the mountains, and caressed by the beneficent breezes of the sea. This concourse of circumstances was necessary in order to produce those beautiful round tops, those lustrous domes of a bright deep green, those innumerable golden apples, and that exquisite fragrant vegetation which, in mid-winter, makes this coast the richest and loveliest of gardens. Let us now reflect on the manner in which things moved in this example. We have just observed the effect of circumstances and of physical temperature. Strictly speaking, these have not produced the orange; the seeds were given, and these alone contained the vital force. The circumstances described, however, were necessary in order that the plant might flourish and be propagated; had these failed, the plant likewise would have failed.