386 REVIEWS—GEOLOGICAL EVIDENCES OF MAN’S ANTIQUITY. 
never any instruments of bronze, still less of iron. The stone knives 
are sharpened by rubbing, and in this respect are one degree less rude 
than those of an older date, associated in France [and in England] with 
the bones of extinct mammalia. The mounds vary in height from 
three to ten feet ; and in area, some of them are 1,000 feet long, and 
from 150 to 200 wide. They are rarely placed more than ten feet 
above the level of the sea, and are confined to its immediate neigh- 
bourhood, or if not (and there are cases where there are several miles 
from the shore), the distance is ascribable to the entrance of a small 
stream, which 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 M. Puggard, by a 
very slow upheaval of the whole country, amounting to two or three 
inches in a century. There is also another geographical fact equally 
in favour of the antiquity of the mounds, viz., that they are wanting 
on those parts of the coasts 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 German Ocean 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 ail, that the 
“‘refuse-heaps”’ 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 shell-mounds the oyster 
‘flourished in places from which it is now excluded. In like manner, 
the eatable cockle, mussel, and periwinkle, which are met with in 
great numbers in the “‘refuse-heaps,” 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 natu- 
ral size, being stunted and dwarfed in their growth by the quantity of 
fresh-water poured by rivers into that inland sea. Hence, we may 
confidently infer that in the days of the aboriginal hunters and fishers, 
the ocean had freer access to the Baltic than at present.” 
The bones of mammalia enclosed in these refuse-heaps belong en- 
tirely to existing forms, with the exception of one species, the Bos 
