Leipzig, Barth, 1909. 8°. XIV, 388 p. Contemp. half cloth. "Zeitschrift f. Psychologie u. Physiologie d. Sinnesorgane", I/4. With the author's ms. dedication on title to Wolfgang Storck.
First edition of this important contribution to experimental psychology by the Stuttgart born E. R. Jaensch (1883-1940). - With the author's ms. dedication to Wolfgang Stock on title.