has deposited sediment, or to the growth of a peaty swamp, by which
the land has been made to advance on the Baltic, as it is still
doing in many places, aided, according to Puggaard, by a very slow
upheaval of the whole country at the rate of 2 or 3 inches in a
century.

There is also another geographical fact equally in favour of the
antiquity of the mounds, namely, that they are wanting on those
parts of the coast which border the Western Ocean, or exactly where
the waves are now slowly eating away the land. There is every
reason to presume that originally there were stations along the
coast of the North Sea as well as that of the Baltic, but by the
gradual undermining of the cliffs they have all been swept away.

Another striking proof, perhaps the most conclusive of all, that
the "kitchen-middens" are very old, is derived from the character
of their embedded shells. These consist entirely of living species;
but, in the first place, the common eatable oyster is among them,
attaining its full size, whereas the same Ostrea edulis cannot live
at present in the brackish waters of the Baltic except near its
entrance, where, whenever a north-westerly gale prevails, a current
setting in from the ocean pours in a great body of salt water. Yet
it seems that during the whole time of the accumulation of the
"kitchen-middens" the oyster flourished in places from which it is
now excluded. In like manner the eatable cockle, mussel, and
periwinkle (Cardium edule, Mytilus edulis, and Littorina littorea),
which are met with in great numbers in the "middens," are of the
ordinary dimensions which they acquire in the ocean, whereas the
same species now living in the adjoining parts of the Baltic only
attain a third of their natural size, being stunted and dwarfed in