I VISITED THE CAVE of Rouffignac on a day of sun showers, but in side it was cold and dark. Rouffignac is what they call a dry cave, which means that it was formed by water moving laterally from a central well, not by seepage from the surface. Thus it has no stalactites, and the walls are relatively smooth. Red stones projecting from the walls are broken off where bears sharpened their claws. Craters in the stone floor were scooped out by bears for their winter-long snoozes. Fifteen thousand years ago, men and bears competed for living space in these caverns of the soft stone cliffs along the Dordogne and V?z?re rivers. Now an electric train carries you two miles into the cliff to see the wall paintings. Whoever drew the figures walked that distance to make those drawings in that spot. He drew three rhinoceros walking in a line. Further on, someone engraved a figure into the soft stone. The guide's flashlight follows the outline of the tusks, the trunk, the rounded skull, the down ward curve connecting skull to hump: a mammoth, suggested with elo quent simplicity. Further on, in a great hall, there are more than sixty fig ures of animals. On the ceiling is a horse so large that whoever painted it could not have seen the whole at once. He had to visualize the propor tions. But there are other sophisticated feats. For one, a frieze of mam moths, two herds of them, coming together nose to nose in the center of a wall. In one herd, a straggler walks a few paces behind the others. Some one composed these images for this space. Someone had an idea on a grand scale and executed it.