ocr: are perfectly expressive of the animal's movement, grace, and speed. The artist has increased the image's power by making the incision slope deeply on one edge, while leaving it quite shallow on the other, thereby casting a shadow onto the horse and pro- viding the illusion of relief. In the dimness of a rock shelter, this effect would have been still more dramatic. The way the shape of the horse echoes that of the limestone into which it was carved 213