From the period claimed by archaeologists we pass by gradual stages into the domain of the geologist. As Huxley wrote, 'when even the dim light of Archaeology fades, there yet remains Palaeontology, which... has brought to daylight once more the exuvia of ancient populations, whose world was not our world, who have been buried in river beds immemorially dry, or carried by the rush of waters into caves, inaccessible to inundation since the dawn of tradition(8).' The length of time represented by a succession of long-lived individuals of the same species becomes enormously extended when we pass to the history of families, and disinter from the sediments of other ages the remains of extinct types. As we descend the geological series familiar types gradually disappear, and through a succession of changing floras we penetrate to the fragmentary records contained in the older rocks until the absence of documents sets a limit to our quest. [Illustration: Fig. 1. _Pinus sylvestris_ Linn, in the Black Wood of Rannoch. (Photograph by Mr A. G. Tansley.)] The Scots pine shares with the oak, the beech, the aspen, the yew, and several other trees the right to be included in the native flora of Britain. In the peat-beds of Scotland even up to 3000 feet above sea-level the stumps of pines occur in abundance, and in many places recent researches have revealed the occurrence of successive forests of pines, oaks, and spruces separated from one another by the accumulations of swampy vegetation(9). The spruce fir has long ceased to be a member of the British flora, but in a few localities in the Scottish Highlands patches of primeval pine forests remain. The accompanying photograph (Fig. 1), taken by my friend Mr A. G. Tansley, in the Black Wood of Rannoch in north-west Perthshire, shows a few trees of _Pinus sylvestris_ growing in their native soil: the form of the older tree (_A_) suggests comparison with that of a well-grown beech such as we are familiar with in English plantations. This spreading dome-shaped habit seems to be a peculiarity of the Highland tree, and is one of the characters which have led some botanists to regard it as a variety (_Pinus sylvestris_ var. _scotica_) of the ordinary Scots pine. Though it is doubtful if any relics of primeval pine woods are left in England, abundant evidence of the former existence of the Scots pine is afforded by the submerged forests exposed at low-tide on many parts of the English and Welsh coasts and at the base of some of the English peat moors. During the construction of the Barry docks on the north coast of the Bristol Channel a few years ago, the exposed sections of peat and forest beds were investigated by Dr Strahan and by Mr Clement Reid. There is evidence of a subsidence of the land to an extent of 55 feet since the formation of the lower peat-beds containing oak, hazel, willow, and other trees. The pine, unknown in Wales during the historic period, was recognised in the Barry cutting.