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.  Esmo was of opinion that the snow on the highest steeps, even on a level plateau, was never more than two feet in depth; and in more than one case a wind-swept peak or pinnacle was kept almost clear, and presented in its grey, green, or vermilion rocks a striking contrast to the masses of creamy white around it.  This may explain the very rapid diminution of the polar ice-caps in the summer of either, but especially of the Southern hemisphere; and also the occasional appearance of large dark spots in their midst, where the shallow snow has probably been swept away by the rare storms of this planet from an extensive land surface.  It is supposed that no inconsiderable part of the ice and snow immediately surrounding the poles covers land; but, though balloon parties have of late occasionally reached the poles, they have never ventured to remain there long enough to disembark and ascertain the fact.