Page:Philosophical Review Volume 1.djvu/706

690 her theory is superior to the older ones especially in two regards: firstly, as rendering intelligible the distribution of the retinal rods and cones; and secondly, as accounting for the fact that red-green and green-blue mixtures appear less saturated than the simple colors. The crucial objection to the hypothesis, as the author sees, is that yellow is for sensation as simple a color as red or green. Nor is the theory helped by the introduction of a conjectural retinal physiology. Finally, judgment must in any case be suspended until the writer has published her promised investigation of the assumptions underlying Hillebrand's alleged proof, that in color-mixtures which arouse the sensation of white the component color-processes cancel one another.

A careful paper, belonging rather to the domain of physiological than of psychological optics, though containing observations which are of interest to the psychologist in connection with the question of the nature of the field of vision.

Lotze's theory of local signs underwent many modifications at its author's hands, and has been still further modified by Wundt. The editor of the Kleine Schriften has called attention to a late utterance of the writer's, in which he describes spaciousness as an attribute of sensation, comparable with quality or intensity. This is the view held by Stumpf and James. The former points out here that it is inconsistent with the general scheme of a local-sign theory. That Lotze inclined towards it, as he inclined in his Metaphysik to a hypothesis more nearly approaching those of Berkeley and Bain, is, he thinks, an indication of the necessity of a nativistic space-psychology.

(1) Zu Dr. Otto Schwarz' "Bemerkungen über die von Lipps u. Cornelius besprochene Nachbilderscheinung." If the eye be rapidly turned away from a bright object, a streak of light seems to shoot from the object in the opposite direction. Lipps explained this phenomenon (Bd. I, S. 60 ff.) as due to the underestimation of quick eye-movements. Dr. Schwarz, who attempted a different explanation (Bd. III,