the fourth century could play upon marble as if it were wax or clay. They could represent textures and surfaces by the degree of their finish, so that the leather of the shoe is of a surface distinct from the skin of the foot in the Hermes of Praxiteles. There is an extremely subtle contrast between the leopard-skin and the flesh of the young Satyr by the same artist in the admirable torso copy which is in the Louvre. Whereas earlier artists had tried to represent hair by grooves gouged out upon the surface of the head or by rendering each tress as a separate thread, Praxiteles discovered the marvellous impression of curls that could be produced by roughly blocking out several masses and leaving the play of light and deep shadow to indicate a surface movable and alive. New secrets of sculptural anatomy were now at command. Praxiteles discovered the value of that groove which runs vertically down the front of the body between the pectoral and abdominal muscles on each