In some few places the peat is still used for fuel, and there is a theory to the effect that peat reek is necessary for the best kinds of Scotch whisky, but neither grouse nor black-faced sheep, which live on the young shoots of the heather, employ in at all a satisfactory way these great stretches of land. Many attempts have been made to spin the silky threads of the Cotton-grass which grows abundantly on the Scotch lowlands. It is neither a grass, nor does it supply cotton, but is called Eriophorum. It is perhaps the one really beautiful plant to be found on them, for its waving heads of fine silky-white hairs are exceedingly pretty. The heather itself gives a splendid red and purple shade, which in summer and autumn is always changing colour, but it is monotonous. Neither the little Bog Asphodel with its yellowish flowers, nor red Drosera, or butter-coloured Butterwort, are particularly beautiful. After seeing such a country one understands something of the Cameronian Covenanters who held their conventicles and took refuge therein. The manner in which these mosses and moors have developed is most interesting, and yet difficult to explain. There are two kinds of peat-mosses, which, although there are many intermediate types, may be kept apart. The first, like the one near Stirling, Lochar and Solway Moss, near Dumfries, and Linwood, near Glasgow, have been formed in low-lying flat estuarine marshes. If one refers back to page 210, it will be seen how reeds and rushes and marsh plants may gradually fill up river backwaters. Eventually a saturated, marshy meadow is produced. Then comes the chance of that wonderful moss the peat-moss, or Sphagnum. It is scarcely possible to appreciate its structure without the help of a microscope and a good deal of trouble in the way of imagination. It is in a small way a sort of vegetable pump which raises water a few inches or so. Stem and leaves and branches possess little cistern cells, which act both as capillary tubes raising the water and also retain it. The stems are upright and develop many branches, so that they become a close-ranked or serried carpet of upright moss-stems squeezed together, which floats on the surface of the water. Each moss-stem is growing upwards and dying off below. In consequence, the bottom gets filled up by dead mossy pieces, which accumulate there, while the live moss-carpet remains floating on the surface of the loathly, black, peaty water. In many peat-mosses the water gets entirely filled up, but that does not stop the formation of the peat-moss. It is now resting on the water-saturated remains of its forefathers, and if water is abundantly supplied it goes on developing.