The same is still better proved as regards the later part of the stone age.  Traces of neolithic man have been found in numberless quantities, so that we can reconstitute his manner of life to a great extent.  When the ice-cap (which must have spread from the Polar regions as far south as middle France, middle Germany, and middle Russia, and covered Canada as well as a good deal of what is now the United States) began to melt away, the surfaces freed from ice were covered, first, with swamps and marshes, and later on with numberless lakes.(5) Lakes filled all depressions of the valleys before their waters dug out those permanent channels which, during a subsequent epoch, became our rivers.  And wherever we explore, in Europe, Asia, or America, the shores of the literally numberless lakes of that period, whose proper name would be the Lacustrine period, we find traces of neolithic man.  They are so numerous that we can only wonder at the relative density of population at that time.  The “stations” of neolithic man closely follow each other on the terraces which now mark the shores of the old lakes.  And at each of those stations stone implements appear in such numbers, that no doubt is possible as to the length of time during which they were inhabited by rather numerous tribes.  Whole workshops of flint implements, testifying of the numbers of workers who used to come together, have been discovered by the archaeologists.

Traces of a more advanced period, already characterized by the use of some pottery, are found in the shell-heaps of Denmark.  They appear, as is well known, in the shape of heaps from five to ten feet thick, from 100 to 200 feet wide, and 1,000 feet or more in length, and they are so common along some parts of the sea-coast that for a long time they were considered as natural growths.  And yet they “contain nothing but what has been in some way or other subservient to the use of man,” and they are so densely stuffed with products of human industry that, during a two days’ stay at Milgaard, Lubbock dug out no less than 191 pieces of stone-implements and four fragments of pottery.(6) The very size and extension of the shell heaps prove that for generations and generations the coasts of Denmark were inhabited by hundreds of small tribes which certainly lived as peacefully together as the Fuegian tribes, which also accumulate like shellheaps, are living in our own times.

As to the lake-dwellings of Switzerland, which represent a still further advance in civilization, they yield still better evidence of life and work in societies.  It is known that even during the stone age the shores of the Swiss lakes were dotted with a succession of villages, each of which consisted of several huts, and was built upon a platform supported by numberless pillars in the lake.  No less than twenty-four, mostly stone age villages, were discovered along the shores of Lake Leman, thirty-two in the Lake of Constance, forty-six in the Lake of Neuchatel, and so on; and each of them testifies to the immense amount of labour which was spent in common by the tribe, not by the family.  It has even been asserted that the life of the lake-dwellers must have been remarkably free of warfare.  And so it probably was, especially if we refer to the life of those primitive folk who live until the present time in similar villages built upon pillars on the sea coasts.