A still more striking example of the preservation of forest trees rooted in an old surface-soil is afforded by the so-called fossil-grove in Victoria Park, Glasgow, (Frontispiece). The stumps of several trees, varying in diameter from about one to three feet, are fixed by long forking ‘roots’ in a bed of shale. In some cases the spreading ‘roots,’ which bear the surface features of _Stigmaria_, extend for a distance of more than ten feet from the base of the trunk. The stem surface is marked by irregular wrinklings which suggest a fissured bark; but the superficial characters are very imperfectly preserved. In one place a flattened _Lepidodendron_ stem, about 30 feet long, lies prone on the shale. Each of the rooted stumps is oval or elliptical in section, and the long axes of the several stems are approximately parallel, pointing to some cause operating in a definite direction which gave to the stems their present form. Near one of the trees, and at a somewhat higher level than its base, the surface of the rock is clearly ripple-marked, and takes us back to the time when the sinking forest trees were washed by waves which left an impress in the soft mud laid down over the submerged area. The stumps appear to be those of Lepidodendron trees, rooted in Lower Carboniferous rocks. From their manner of occurrence it would seem that we have in them a corner of a Palaeozoic forest in which Lepidodendra played a conspicuous part. The shales and sandstones containing the fossil trees were originally overlain by a bed of igneous rock which had been forced up as a sheet of lava into the hardened sands and clays[68]. Other examples of old surface-soils occur in different parts of the world and in rocks of various ages. As an instance of a land surface preserved in a different manner, reference may be made to the thin bands of reddish or brown material as well as clays and shale which occasionally occur between the sheets of Tertiary lava in the Western Isles of Scotland and the north-east of Ireland. In the intervals between successive outpourings of basaltic lava in the north-west of Europe during the early part of the Tertiary period, the heated rocks became gradually cooler, and under the influence of weathering agents a surface-soil was produced fit for the growth of plants. In some places, too, shallow lakes were formed, and leaves, fruits and twigs became embedded in lacustrine sediments, to be afterwards sealed up by later streams of lava. In the face of the cliff at Ardtun Head on the coast of Mull a leaf-bed is exposed between two masses of gravel underlying a basaltic lava flow; the impressions of the leaves of _Gingko_ and other plants from the Tertiary sediments of this district are exceptionally beautiful and well preserved[69]. A large collection obtained by Mr Starkie Gardner may be seen in the British Museum.