898 In order to follow, R must pass the mirror again and the rail momentarily disappears, changes again into a road-runner moving in the same direction as Rhody, but stopping and looking at him as he does the same, only to disappear as the rail comes into view again. All of this is very perplexing to Rhody, whose knowledge of optical phenomena is strictly circumscribed by his own experience. He paus- es, stares at the rail and seems to be trying to arrive at the explanation of the mystery by a process of pure reason, in which endeavor he is, unfortunately, severely handicapped by inadequate mental equipment. On the present occasion this sort of thing continued for a full half hour before R gave up and went off to "think" with his back toward the cage. As if to relieve his mind, he suddenly ran up the old oak at tremendous speed and dived off the top into the glade. It looked like suicide, but when I approach- ed, he was sitting calmly on the ground listening to the sounds of birds in the bushes and doubtless wondering when there would be ests to rob. Brownie spied me and came for worms. Rhody watched this for a time, then came too without invitation. B did not altogether like the intrusion, but was compelled to receive worms alternately with Rhody, and somewhat suspiciously. R disregarded B. R suddenly stretched to his full height and stared fixedly at something behind me. It proved to be a large cat about 50 feet away, which turned and ran, as I turned to look, toward the vacant lot to the east. To my surprise, R immediately followed on a slightly diverging course, down the driveway to the sidewalk at the entrance where he stood for several minutes staring up into the lot where the cat had gone. Tiring of this he suddenly ran swiftly along the street, due west, spread his wings after running about 25 yards, sailed for the next 50 yards in an upwardly curving are not more than 3 feet above the street (which is level) at