In the mountain range or Zagros and the tracts adjacent to it, the climate, owing to the great differences of elevation, is more varied than in the other parts of the ancient Media. Severe cold prevails in the higher mountain regions for seven months out of the twelve, while during the remaining five the heat is never more than moderate. In the low valleys, on the contrary, and in other favored situations, the winters are often milder than on the plateau; while in the summers, if the heat is not greater, at any rate it is more oppressive. Owing to the abundance of the streams and proximity of the melting snows, the air is moist; and the damp heat, which stagnates in the valleys, broods fever and ague. Between these extremes of climate and elevation, every variety is to be found; and, except in winter, a few hours’ journey will almost always bring the traveller into a temperate region. In respect of natural productiveness, Media (as already observed) differs exceedingly in different, and even in adjacent, districts. The rocky ridges of the great plateau, destitute of all vegetable mold, are wholly bare and arid, admitting not the slightest degree of cultivation. Many of the mountains of Azerbijan, naked, rigid, and furrowed, may compare even with these desert ranges for sterility. The higher parts of Zagros and Elburz are sometimes of the same character; but more often they are thickly clothed with forests, affording excellent timber and other valuable commodities. In the Elburz pines are found near the summit, while lower down there occur, first the wild almond and the dwarf oak, and then the usual timber-trees of the country, the Oriental plane, the willow, the poplar, and the walnut. The walnut grows to a large size both here and in Azerbijan, but the poplar is the wood most commonly used for building purposes. In Zagros, besides most of these trees, the ash and the terebinth or turpentine-tree are common; the oak bears gall-nuts of a large size; and the gum-tragacanth plant frequently clothes the mountain-sides. The valleys of this region are full of magnificent orchards, as are the low grounds and more sheltered nooks of Azerbijan. The fruit-trees comprise, besides vines and mulberries, the apple, the pear, the quince, the plum, the cherry, the almond, the nut, the chestnut, the olive, the peach, the nectarine, and the apricot.