Considerably more light is thrown on this question when we examine the products of human activity, such as implements, weapons, and works of art. Traces of man, in the form of objects hammered out of flint and shaped into clubs, chisels, knives, and daggers, capable of serving as implements of daily use no less than as weapons, are to be found as far back as the first diluvian epoch, and, in their crudest forms, perhaps even as early as the tertiary period. The more polished objects of similar form belong to a later age. Still more remarkable are the works of art--in particular, the cave pictures of prehistoric animals, such as the cave bear and the mammoth. Nevertheless, none of these achievements is of such a nature as to afford positive evidence of a culture essentially different from, or lower than, that of the primitive man of to-day. Two outstanding facts, especially, make a comparison difficult. On the one hand, wood plays an important rôle in the life of modern primitive man, being used for the construction of tools, weapons, and, in part, also of baskets and vessels. But the utensils of wood that may have existed in prehistoric times could not have withstood the destructive forces of decomposition and decay. All such utensils, therefore, that prehistoric man may have possessed have been lost. Thus, for example, it will be difficult ever to ascertain whether or not he was familiar with the bow and arrow, since the arrow, as well as the bow, was originally made of wood. Secondly, there is at the present time no primitive tribe, however much shut off from its more remote environment, into which barter, which is nowhere entirely absent, may not introduce some objects representing a higher form of civilization, particularly metals and metal implements. If, however, we bear in mind that, in the one case, products have suffered destruction and that, in the other, articles have been introduced from without, the impression made by prehistoric utensils and products of art--aside from certain doubtful remains dating back beyond the diluvial epoch--is not essentially different from that made by the analogous products of the Negritos of the Philippines or the inland tribes of Ceylon. Though the material of which the implements are constructed differs, the knives, hammers, and axes in both instances possess the usual form. Thus, the wooden knife which the Veddah of Ceylon still carves out of bamboo is formed precisely like some of the stone knives of the diluvial period. We find a similar correspondence when we examine the traces of dwellings and decorations that have been preserved, as well as certain remains that throw light upon customs. The oldest prehistoric people of Europe dwelt in caves, just as the primitive man of the tropics does to-day in the rainy season. In a rock cavern near Le Moustier, in France, there was discovered a skeleton whose crouching position points to a mode of burial still prevalent among primitive peoples, and one which is doubtless always a fairly positive indication of a belief in demons such as arises in connection with the impression made by death. The dead person is bound in the position that will best prevent his return. Thus, all these prehistoric remains suggest a culture similar to that of primitive tribes of to-day. But, just because they reveal conditions not essentially different from those of the present, these remains make another important contribution to our knowledge of primitive man. They indicate the great stability of primitive culture in general, and render it probable that, unless there are special conditions making for change, such as migrations and racial fusions, the stability increases in proportion to the antiquity. Though this may at first glance seem surprising, it becomes intelligible when we consider that isolation from his surroundings is an important characteristic of primitive man. Having very little contact with other peoples, he is in no wise impelled to change the modes of action to which his environment has led him from immemorial times.