A HISTORY OF SURREY leaving a balance of no less than 113,661 acres represented by waste lands. With regard to the principal soils, I think that there is no doubt that the Bagshot Sands is by far the hottest and driest and most sterile in the county. The Lower Greensand comes next, and I have no hesi- tation in placing the chalk midway between the sands and the heavier clays. Porous as the chalk undoubtedly is, there is always a certain amount of moisture to be found a little way below the surface, and farmers find that in very hot and dry seasons the corn crops, which are not deep rooters, suffer less on the chalk than on even the Lower Green- sand. Last come the clays the Gault, Wealden, and London Clay. It will be convenient to speak first of the southern portion of the county, both because we find here the oldest geological formations, and because these correspond to the upper waters of the chief rivers. The Weald Clay stretches in an unbroken belt across the south of the county from east to west ; broadest at the eastern end and narrowing irregularly westwards until near Haslemere it disappears, so that the extreme west is devoid of this formation. It is characterized generally by its flatness and an absence of any high hills, by an alternation of cultivated land, green woods and copses of oak, willow, etc., and more or less extensive commons covered with scattered bushes of gorse (U/ex europceus), but without the heaths (Erica), although the ling (Calluna) occurs, and by a general absence of pine woods. The coral-root (Dentaria bulbifera) is confined to this formation as well as two pondweeds (Potamogeton Jluitans and P. decipiens). The Lower Greensand which follows affords the two highest points in the county, Leith Hill (965 feet) and Hind Head (840 feet). Un- like the Wealden, the Lower Greensand is very narrow at its eastern end, expanding towards the west. The pine woods, very extensive in parts, notably in the region lying between Leith Hill and Pitch Hill and about Hind Head, together with the heaths (Erica tetralix and E. cmerea), which now become abundant, alone suffice to give a very distinctive character to this formation as compared with the last. The peculiar species also are more numerous, and there may be mentioned a bitter-cress (Cardamine impatient), a very rare waterwort (Elatine Hydro- piper), the sea stork's-bill (Erodium maritimum), brookweed (Samolus Valerandf), and the following members of the sedge family : Cyperus fuscus, Rbynchospora fusca, Carex arenaria and G. depauperata. The chalk and gault belt again has its widest part at the eastern end of the county, narrowing towards the west, until the extremely narrow ridge of the Hog's Back is reached. This formation presents a strong personal observations made in all parts of the county, seconded by communications with which I have been favoured by numerous correspondents. To these I desire to express my best thanks, as well as to Mr. S. W. Carruthers for his extracta of prae-Linnean records, to Mr. G. S. Boulger for his valuable advice in connection with the delimitation of the districts, and particularly to the Rev. W. Moyle Rogers, author of a Handbook of the British Rubi, Mr. Harold W. Monington, Messrs. W. and G. S. West, Mr. E. M. Holmes, and Mr. George Massee for their kindness in contributing papers on the Surrey Brambles, Mosses, Algae, Lichens and Fungi respectively. 36
