CHAP. II. OR " KITCHEN-MIDDENS." 13 



of the antiquity of the mounds, viz., that they are wanting 

 on those parts of the coast which border the Western Ocean, 

 or exactly where the waves ai"e 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 

 all, that the ''refuse-heaps" are very old, is derived from 

 the character of their imbedded shells. These consist en- 

 tirely of living species; but, in the tirst 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, when- 

 ever a northwesterly gale prevails, a current setting in from 

 the ocean pours in a great body of salt water. Yet it seems 

 that during the w^hole 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 {Cardium edule, Mytilus edulis, 

 and Littorina littorea), which are met with in great 

 numbers in the " refuse-heaps," are of the ordinary dimen- 

 sions 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 their growth by the quantity of fresh water 

 poured by rivers into that inland sea.* Hence we may con- 

 fidently infer that in the days of the aboriginal hunters and 

 fishers the ocean had freer access than liow^ to the Baltic, 

 communicating probably through the peninsula of Jutland, 

 Jutland having been at no remote period an archipelago. 

 Even in the course of the present century, the salt waters 



* See Principles of Geology, eh. xxx. 



