In this investigation the author undertook to study the variations in the reproduction of geometrical patterns shown tachistoscopically to his observers, and to relate the difference to the observers' reports upon the nature of the perception. The types of changes are compared with those reported by Wulf in a previous investigation of the changes in memory images which occur with a lapse of time. (Psychol. Forsch., 1922, 1, 333 ff.) Two series of simple geometrical figures were used as the material, the one series consisting of 14 figures made up of straight lines, and the other, 14 figures made up of curved lines, including 4 figures that involved both straight-line and curved-line components. The figures were exposed to the subjects by a modified Ranschburg memory apparatus for approximately 1½ seconds. No definite time limit was set for reproduction. Six observers participated in the experiment, making approximately 4,000 reproductions of the 28 figures. An analysis of the types of changes introduced by the observer in the reproductions of the figures showed trends in the direction of making them similar to objects frequently associated with the figures in previous perceptions. Also changes were often found to be conditioned by cues furnished from a verbal analysis made during the perception of the form. Closure, or perceptual filling, and analysis, or falling apart into separate units, were characteristics likewise. Curved lines are much more apt to be reproduced as straight lines than the reverse. In general, the nature of a change found in the reproduction depends upon the manner in which the figure was apprehended. (PsycINFO Database Record (c) 2006 APA, all rights reserved)