1. Parts of the picture under these conditions may be seen as detached from the screen, undistorted, and situated in a frontal-parallel plane in the intervening space. What is said here about distortion refers to those parts of the picture remaining phenomenally on the plane of the screen.
2. K. Koffka, Psychol. Forsch.16, 329–354 (1932).
3. Egon Brunswik, Z. Psychol.109, 40–115 (1929).
4. Egon Brunswik, Arch. f. Psychol.88, H. 3/4 (1933).
5. Brit. J. Psy chol.22, 344 (1931).