SHELL-MOUNDS or KITCHEN-MIDDENS (Dan. Kjokken-modding), prehistoric refuse heaps or mounds, found in all quarters of the globe, which consist chiefly of the shells of edible molluscs mixed with fragments of animal bones, and im plements of stone, bone and horn. They may sometimes, as in the Straits of Magellan, be seen in process of formation.
Many, of prehistoric origin, have been examined, notably on the eastern coast of Denmark. These were at first thought to be raised beaches, but a cursory examination at once proved their artificial construction. Further investigation proved these shell mounds to belong to the early part of the Neolithic age (q.v.). They contained the remains of quadrupeds, birds and fish, the food of the prehistoric inhabitants. Among the bones were those of the wild bull or aurochs, beaver, seal and great auk, all now extinct or rare in this region. Moreover, shell-mounds contain full sized shells of the common oyster, which cannot live at pres ent in the brackish waters of the Baltic except near its entrance, the inference being that the shores where the oyster at that time flourished were open to the salt sea. Thus also the eatable cockle, mussel and periwinkle abounding in the kitchen-middens are of full ocean size, whereas those now living in the adjoining waters are a third of full size, owing to the want of saltness. This exten tion of the North sea is called the "Littorina sea"; and it existed round about 4000-3000 B.c., the end of Brooks's Maritime period. The debris is in some places 'oft. to loft. thick.
The men of the kitchen-middens had seemingly no knowledge of agriculture, no traces of grain of any sort being found. The only vegetable remains were burnt pieces of wood and some charred substance, possibly a sea-plant used in the production of salt. Flat stones blackened with fire, forming hearths, were also found. That periods of scarcity must have been frequent is indi cated by the discovery of bones of the fox, wolf and other car nivora, which would hardly have been eaten from choice. The
kitchen-middens of Denmark were not mere summer-quarters; the ancient fishermen appear to have stayed in the neighbourhood for two-thirds, if not the whole of the year, since by examination of the bones of the wild animals it is often possible to tell the time of year when they were killed. Thus the remains of the wild swan (Cygnus musicus), a winter visitor, leaving the Danish coast in March and returning in November, are found in abundance. Additional proof is afforded among the mammalian remains by two periodical phenomena, the shedding of the stag's antlers and the birth and growth of the young. The flint implements found include flakes, axes, awls, sling-stones or net-weights, and rude lance-heads. A fragment of one polished axe was found, at Ha velse, which had been worked up into a scraper. Small pieces of coarse pottery are also met with, the typical vessel having a pointed base. The Danish kitchen-midden men were not cannibals. They seem to have resembled the Lapps, small men with heavy over-hanging brows and round heads.
At Omori (Japan), in the Aleutian islands, in British Columbia, Oregon and California shell-mounds were explored, and always proved that the present populations had been preceded by ruder tribes of great antiquity. On the Atlantic coast of Brazil shell mounds, which must have taken thousands of years to accumulate, are now overgrown with dense forests. Shell-mounds also occur round the coasts of Britain, at Chark near Gosport, inland at Blashenwell farm, Dorset, at Harlyn bay in Cornwall and in Cork harbour, but there is no reason to suppose all these deposits to be contemporary. The shell-mounds on the west coast of Scot land are of ten associated with raised beaches.