from which you look at it. Every tor also has its heap of rock at its feet, some of them very striking jumbles of blocks of granite scattered in great confusion between the tor and the foot of the hill. Fur Tor, which is in the very wildest spot on Dartmoor, and is one of the leading tors, has a _clitter_ of rocks on its western side as remarkable as the tor itself; Mis Tor, also on its western side, has a very fine clitter of granite; Leather Tor stands on the top of a mass of granite rocks on its east and south sides; and Hen Tor, on the south quarter, is surrounded with blocks of granite, with a hollow like the crater of a volcano, as if they had been thrown up by a great convulsion of Nature. Hen Tor is remarkable chiefly for this wonderful mass of granite blocks strewn around it. All the moor has granite boulders scattered about, but they accumulate at the feet of the tors as if for their support."[3] [Illustration: VIXEN TOR] Here among the clitters, where they form caves, a search may be made for the beautiful moss _Schistostega osmundacea_. It has a metallic lustre like green gold, and on entering a dark place under rocks, the ground seems to be blazing with gold. In Germany the Fichtel Gebirge are of granite, and the Luchsen Berg is so called because there in the hollow under the rocks grew abundance of the moss glittering like the eyes of a lynx. The authorities of Alexanderbad have had to rail in the grottoes to prevent the _gold moss_ from being carried off by the curious. Murray says of these retreats of the luminous moss:-- "The wonder of the place is the beautiful phosphorescence which is seen in the crannies of the rocks, and which appears and disappears according to the position of the spectator. This it is which has given rise to the fairy tales of gold and gems with which the gnomes and cobolds tantalise the poor peasants. The light resembles that of glow-worms; or, if compared to a precious stone, it is something between a chrysolite and a cat's-eye, but shining with a more metallic lustre. On picking up some of it, and bringing it to the light, nothing is found but dirt." Professor Lloyd found that the luminous appearance was due to the presence of small crystals in the structure which reflect the light. Coleridge says:-- "'Tis said in Summer's evening hour, Flashes the golden-coloured flower, A fair electric light." In 1843, when the luminosity of plants was recorded in the _Proceedings of the British Association_, Mr. Babington mentioned having seen in the south of England a peculiar bright appearance produced by the presence of the _Schistostega pennata_, a little moss which inhabited caverns and dark places: but this was objected to on the ground that the plant reflected light, and did not give it off in phosphorescence.[4]