“Well,” said George, “I think when Bunny, standing on the left side of the driveway calls Patter’s name, the dog will turn to him, and that will make him press a little on the left rein and Toby will go that way. Then if Sue calls Patter from the right hand side of the drive, Patter will turn to look at her, and his right paw will press on the right rein and Toby will turn that way.”