32 ADAMITES AND PREADAMITES.
gravels are chiefly articles of rough stone and bone. With these are associated some remains of extinct quadrupeds. Some alluvial deposits near Strasburg, and at Maestricht and elsewhere, have afforded rude flints and human bones. In the volcanic mountain of Denise, in Central France, human bones have been found imbedded in volcanic tuff; and in another locality tuff resulting from the same eruption encloses the remains of a cave-hyena and a hippopotamus.
Again the peat-bogs of Denmark have afforded a rich series of relics chronologically arranged. These bogs are from ten to thirty feet deep. In the lowest portions they enclose remains of the scotch fir, a tree no longer growing in Denmark; and with these are associated implements of flint. Above are found traces of the common oak, now very rare in Denmark, and, associated therewith, implements and ornaments of bronze, as well as stone. But in the highest portions of the peat are found the re-mains of the beechen forest now living, and mingled with these are relics of an age of iron. The bogs of Ireland have been correspondingly productive.
The kitchen-middens, or kitchen refuse heaps, are piles of earth and human relics occurring along the shores of Denmark, reaching sometimes a height of ten feet, with a breadth of 200 and a length of 1,000. They are largely made up of the shells of the oyster, cockle and other edible molluscs, but these are plentifully mingled with the bones of various quadrupeds, birds and fishes, which have served as food. Interspersed with these offal accumulations are flint knives, hatchets and other instruments of stone, horn, wood and bone, with fragments of coarse pottery. No traces of bronze or iron occur. Such refuse heaps lie upon the shores of many other countries, and have been de-scribed in America, from Florida to Maine.
The megaliths or huge roughly hewn blocks of stone, arranged in rude structures, abound in nearly all the countries of Europe. Those called " dolmens " are enormous slabs resting horizontally on upright stones. "Menhirs " are huge stone posts, sometimes standing singly, and sometimes surrounding a dolmen, when they constitue what is called a "cromlech." The "dolmens " were for centuries regarded as the stone altars of the ancient