The crest of the full-grown trees rises about fifty feet above the ground. The air circulates freely under the leafy canopy formed by their interlacing branches, but the sun's rays do not penetrate. Shade, air, and water--these three elements permit the most varied cultivation in the palm-gardens, despite the scorching heats of summer. The fruit trees which flourish are the fig, the pomegranate, the apricot; less frequently, the vine and the olive; still more rarely, the peach, the pear, and the orange. Vegetables are commonly cultivated during winter; such as turnips, cabbages, onions, carrots, beans, and pimento (_Capsicum annuum_), an indispensable condiment for those Arab sauces (_merga_) destined to stimulate the digestive energies of a people who abstain from alcoholic liquors. You may also remark pumpkins, gourds, and water-melons; small squares of lucerne, which yield as many as eight crops yearly; the henna (_Lawsonia inermis_), which tints with yellow the nails of the Arab women; and tobacco (_Nicotiana rustica_), cultivated most largely in the Souf. In winter you may refresh your eyes in the clearings of the oasis with verdurous fields, green with barleys and early wheats springing vigorously from the earth. The cultivation of cotton, though considerably stimulated by the failure of the usual supply from the Southern States of America, is still in its infancy. There can be little doubt, however, that with improved methods of irrigation it will be considerably and successfully developed. * * * * * The oases of the table-land region, fertilized, as we have already seen, by the streams of fresh water which flow down from the mountains and spread abroad in natural or artificial channels, are much the most fertile, and also the most healthy. They possess, moreover, the inestimable advantage of being but a short distance from the Mediterranean region, in a country less arid and less desolate than the remainder of the Desert. I may name, among these oases, those of El-Kantara, Biskra, and El-Outaïa, which form a sort of chaplet, and are watered by the same river.