The works of art produced by the cave-men are, as we have already seen, of five kinds or classes–(1) All-round small statuettes, or "high-relief" carvings, in ivory, bone, or stone (examples of which are shown in Figs. 14, 25, 26, 27, 28 of the present chapter); (2) small engravings on bits of ivory, deer's antler, bone, or stone (examples are shown in Figs. 15, 16, 20, and 24); (3) large statues, hewn in rock, and left in place; (4) drawings of large size–two to five feet in diameter (partly engraved and partly coloured) on the rocky walls and vaults of limestone caverns (shown in Figs. 11, 12, 13, 17, 18, 19, 23, as well as in the figures of mammoths in the last chapter); (5) models (high relief) worked in clay. I give reproductions in the present chapter of several samples of this art, showing how skilfully these men of 50,000 years ago could portray a variety of animals. Who were these men, and why did they make these remarkable carvings and drawings? First, as to their age. We now know of a long succession of human inhabitants of this part of the world, namely, Western Europe. The earliest reach back to an antiquity never dreamed of fifty years ago. We cannot fix with any certainty the number of thousands, or hundreds of thousands, of years which is represented by this succession, but we can place the different periods in order, one later than the other, each distinguished chiefly by the character of the workmanship belonging to it, though in a few instances we have also the actual limb-bones, skulls, and jaw-bones of the men themselves, which differ in different periods. It is practically certain that these prehistoric successive periods of humanity do not represent the steps of growth and change of one single race belonging to this part of the world, but that successive races have arrived on the scene of Western Europe from other parts, and it is usually very difficult even to guess where they came from and where they went to! It is convenient to divide the human epoch, the time which has elapsed since man definitely took shape as man–characterized by his large brain, small teeth, upright carriage, and large opposable thumb and still larger and more peculiar non-opposable great toe–into the historic and the prehistoric sections. In this part of the world (Europe) the first use of metals (first of all copper, then bronze, and then iron), as the material for the fabrication of implements and tools of all kinds, occurs just on the line between the historic and the prehistoric sections; that is to say, between those times of which we know something by tradition and writing, and those earlier times of which we have no record and no tradition, but concerning which we have to make out what we can by searching the refuse heaps and ruins of man's dwelling-places and carefully collecting such of his "works" as have not utterly perished, whilst noting which lie deeper in the ground, which above and which below the others.