It is certain that since they were heaped up important changes have taken place in Denmark—changes in geography, in fauna, in flora. The sea line has changed; these heaps were formed at the water's edge—to-day many of them are at a considerable distance from the sea. The Baltic has become so fresh that oysters, once abundant and very large, have abandoned its waters. The hollows in the glacial deposits, during the centuries that have elapsed since the ice sheet withdrew, have gradually filled with 
Fig. 7.—Blunt Arrowhead. Flint. peat formed by the decay of successive generations of plant life. The peat tells its own story to the geologist and declares that Denmark was clad in coniferous forests after the Glacial period; later it was covered with oak growth; at present, and for centuries past, beech has been the main arboreal product. Ah, well! the "kitchen middens" go back to the time of the evergreen forests. Bones of the capercailzie or blackcock are found in the shell heaps; this bird dwells no longer in Denmark, and it lives only on the buds of certain conifers. When these old gatherers of shellfish and hunters of stags lived here the Urus still inhabited Jutland, and game of many kinds was abundant.
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| Fig. 8.—Unpolished Celt. Flint. |
Fig. 9.—Polished Celt or Hatchet. Flint. | |
A year since we visited a shell heap in West Jutland that was being excavated under the direction of Mr. Neergaard, assistant of the museum. Located at the edge and on the slope of a terrace, at some little distance from the sea, it extended for many metres along the terrace, presenting a width of several metres and a maximum thickness of 1·75 metre. It had been cut across by a
