I do not think that we have any idea of the slowness with which the lichens spread; a century to them is nothing--it passes as a watch in the night. There is a granite post I often go by. It was set up just seventy years ago, and on it the largest golden circle of the _Physcia parietina_ has attained the diameter of an inch. Mr. Parfitt mentions in connection with it a rocky crag at Baggy Point, North Devon, where it covers the whole surface with a coat of golden colour. It spreads more rapidly on slate than it does on granite, and especially on such slates as are liable to rapid disintegration. The Woodland and the Coryton slates are readily attacked by it. The growth begins with a splash about the size of a sixpence, and increases to that of a plate, when the centre breaks up, and the ring becomes detached in fragments which meet others, and so appear to cover the rock or roof. One of the most beautiful of the lichens on the moor is the coral moss, _Sphærophoron coralloides_. It is a pale greenish-white, upright-growing lichen, that forms a cup, and somewhat resembles an old Venetian wineglass. Then points of brilliant scarlet form round the lip of the cup, and increase in size till the whole presents a wonderful appearance as of sealing-wax splashed over the soil. It is not confined to the moorland, but grows also in woods, where there has been a clearance made. I came upon a wonderful carpet of sprinkled scarlet and white on one occasion, where there was a woodman's track through an old oak coppice. But it must be capricious, for of late years when searching for it in the same spot I have found no more. The black coral moss is scarce, but it has been found about Lynx and Yes Tors.