The lower parts of the Valley of the Somme, far above Amiens and below Abbeville, as far as the sea, are covered with a bed of peat, in some places more than thirty feet thick. Near the surface of these moor grounds Gallo-Roman remains have been found, and, still deeper, Celtic weapons of the stone period; but the thickness of the superincumbent vegetable matter is far inferior to that of the underlying peat, so that many thousands of years must necessarily have passed since the first growth of that swampy vegetation. But, however remote its age, it is still of later date than the adjoining or underlying alluvial deposits of clay, gravel, and sand, which cannot originally have ended abruptly as they do now, but must have once been continuous further towards the centre of the valley. A long time must necessarily have elapsed between their deposition and subsequent denudation, and the first growth of the peat. In the lowest, and consequently oldest, of these beds, there has been found also a mixture of freshwater and marine shells, bones of the primitive elephant and teichorhine rhinoceros, and a number of flint implements shaped by the hands of man. Thus we have here convincing proofs that a race of savages inhabited the Valley of the Somme long before it was scooped out to its present depth, and when as yet not a trace existed of the thick bed of peat which now covers its lower grounds, and required so many thousand years for its formation. Similar flint implements, in connexion with the bones of extinct animals, have been disinterred from ancient drift formations in many parts of England—in Surrey, Middlesex, Kent, Bedfordshire, and Suffolk. In the British Museum there is, among others, a flint spear-headed weapon which was found with an elephant’s tooth near Gray’s Inn Lane in 1715. When, according to the old myth, Evander led Æneas over the site of future Rome, they saw the cattle grazing in what was to be the Forum, and heard them bellowing among the future dwellings of the rich senators and knights, ——‘passimque armenta videbant Romanoque Foro et lautis mugire Carinis.’ The change thus pointed out by Virgil was far less than that exemplified by these few relics of a time when possibly no intervening sea separated Britain from the rest of the world. CHAPTER XXI. TROGLODYTES OR CAVE-DWELLERS—CANNIBAL CAVES. Cave Dwellings in the Val d’Ispica—The Sicanians—Cannibal Caves in South Africa—The Rock City of the Themud—Legendary Tale of its Destruction.