Presently, as we followed the course of the stream, we lost sight altogether of the rapidly dwindling patches of colour representing the enclosures of Ecasfe. On our left, at a distance varying from three to five miles, but constantly increasing as the stream bent to the northward, was the mountain range I had scanned in my descent. On our right the plain dipped below the horizon while still but a few feet above the level of the river; but in the distant sky we discerned some objects like white clouds, which from their immobility and fixedness of outline I soon discovered to be snow-crowned hills, lower, however, than those to the northward, and perhaps some forty miles distant. The valley is one of the richest and most fertile portions of this continent, and was consequently thoroughly cultivated and more densely peopled than most parts even of the Equatorial zone. An immediate river frontage being as convenient as agreeable, the enclosures on either bank were continuous, and narrow in proportion to their depth; the largest occupying no more than from one hundred and fifty to two hundred yards of the bank, the smaller from half to one quarter of that length. Most had a tunnel pierced under the road bordering the river, through which the water was admitted to their grounds and carried in a minute stream around and even through the house; for ornament rather than for use, since every house in a district so populous has a regular artificial water supply, and irrigation, as I have explained, is not required. The river itself was embellished with masses of water-flowers; and water-birds, the smallest scarcely larger than a wagtail, the largest somewhat exceeding the size of a swan, of a different form and dark grey plumage, but hardly less graceful, seemed to be aware of the stringent protection they enjoyed from the law. They came up to our boat and fed out of Eveena's hand with perfect fearlessness. I could not induce any of them to be equally familiar with myself, my size probably surprising them as much as their masters, and leading them to the same doubt whether I were really and wholly human. The lower slopes of the hills were covered with orchards of every kind, each species occupying the level best suited to it, from the reed-supported orange-like _alva_ of the lowlands to the tall _astyra_, above which stretched the timber forests extending as high as trees could grow, while between these and the permanent snow-line lay the yellowish herbage of extensive pastures. A similar mountain range on earth would have presented a greater variety of colouring and scenery, the total absence of glaciers, even in the highest valleys, creating a notable difference. The truth is that the snows of Mars are nowhere deep, and melt in the summer to such an extent that that constant increase whose downward tendency feeds Terrestrial glaciers cannot take place. Probably the thin atmosphere above the snow-line can hold but little watery vapour.