PHILOSOPHICAL PERIODICALS. 439 We must distinguish between memory proper and power of observation (Merkfdhigkeit). Both rest upon impression (Einpragung) and power of associative observation ; memory depends more upon the former. Imbecility is characterised by impressionableness, with lack of power of associative observation ; acquired feeble-mindedness shows a fair activity of association, with defective impressionableness. The main defect of congenital feeble-mindedness lies in defect of apperceptive disposition (Anlage).] M. Foth. ' Wie rahmen wir unsere Bilder ein ? ' [Negatively, the frame rules out from the picture the distracting im- pressions that surround it ; positively, it should further the associations upon which aesthetic illusion depends. Hence the colour of the frame should be chosen to correspond, as far as possible, with the natural surroundings of the scene or object shown in the picture.] R. Hohen- emser. 'Die Quarte als Zusammenklang.' [By its vibration-ratio of 3 : 4 the fourth is the first chord whose natural base or fundamental lies not in the lower but in the higher of the component tones. At the same time, the lower tone, as lower, presents itself as base or fundamental. It is the conflict thus arising which gives the fourth its peculiar harmonic character.] Literaturbericht. W. Muench, J. Trueper, W. Ament. ' Kongress fiir Kinderforschung und Jugend- flirsorge.' Bd. xli., Heft 4. D. Katz. 'Ein Beitrag zur Kenntnis der Kinderzeichnungen.' [The child draws, not what he sees, but what he knows to be present in the object or picture. This fact raises the question of the injection of meaning into sense complexes. The author offers an explanation in terms partly of vision itself (symmetrical position of the eyes ; maximal clearness of apprehension), partly of the co-operation of sight and touch.] E. Jaensch. ' Ueber die Beziehungen von Zeitschiitzung und Bewegungsempfindung.' [We have apparently direct sense criteria only for the rate of movements, not for their length. Associative processes give us our bearings as regards position and atti- tude of the limbs. If now we are asked to execute two movements of the same length from different starting-points, neither of these criteria, the direct or the indirect, are adequate. We therefore have recourse to another set of associations, and estimate in terms of time.] E. Jaensch. ' Ueber Tiiuschungen des Tastsinns : im Hinblick auf die geometrisch- optischen Tiiuschungen.' [First part of an experimental report on cu- taneous illusions of filled and empty space.] Literaturbericht. ARCHIV FUR DIE GESAMTE PSYCHOLOGIE. Bd. vi., Heft 4. A. Kirsch- mann. ' Normale und anomale Farbensysteme.' [(1) The use of the direct must be supplemented by that of the inverted spectrum. Both show mix- tures of wave-lengths ; and the quality of visual sensation depends upon the absence rather than upon the presence of a certain group. (2) Colour systems must be achromatic, dichromatic or polychromatic ; the ' com- ponent ' theories are artificial constructions. (3) The invariable colours of indirect vision are no proof of a component theory ; on the contrary, they are necessary consequences of the changes undergone by a poly- chromatic system with change of retinal position (change in the form of the base of the double cone).] A. Lchmann. ' Beitrage zur Psycho- dynamik der Gewichtsempfindungen.' [Raises the questions whether facilitation (Bahnung) is the cause of the Fechnerian negative time error, of anomalous differences and of typical tendencies, and whether the positive time error may be explained by the conditions of experi- mentation. The experiments were made in Fechner's way, mainly by the method of limits, with a control by the method of constant differ- ences. The law of facilitation is confirmed ; the positive time error
