-584 PHILOSOPHICAL PERIODICALS. points de vue de Eeid, Condillac et M. de Tracy sur 1'idee de 1'existence ou le jugement d'exteriorite ' ; 'Notes sur Malebranche '. 14 Annee, No. 4, July, 1906. Sully Frudhomme. 'Psychologic du libre arbitre.' [A defence of the freedom of the will. The idea of freedom could never have arisen, even as an illusion, if all things were necessarily determined. By its very existence it proves its objective validity.] A. Fouillee. 4 La doctrine de la vie chez Guyau, son unite et sa portee.' E. Halevy. "* Les principes de la distribution des richesses.' Livres nouveaux, etc. ZEITSCHRIFT F. PSYCHOLOGIE. Bd. xli., Heft 5 u. 6. L. Burmester. ^Theorie der geometrisch-optischen Gestalttauschungen, I.' [General discussion of the illusions of conversion which appear in inonocularly fixated objects : illustrations from rectangular sheet of cardboard, leaves of cardboard bent at a right angle, cube, model of stair ; influence of shadows, illumination, surroundings, magnitude and nature of object, practice, etc. Detailed account of observations on the rectangular sheet of cardboard, and deduction of the fundamental theoretical relations.] JL. Oelzelt-Newin. ' Beobachtungen liber das Leben der Protozoen. [A strong plea for the ascription of mental processes to the lowest forms of animal life. Discussion of sensations of the chemical sense, sensations of touch, sensations of warmth, sensations of the static sense, sensations of movement, sensations of light, ideas, feelings and will, in various forms of unicellular organisms. Remarks on Hydra.] E. Jaensch. ' Ueber Tauschungen des Tastsinns, im Hinblick auf die geometrisch- optischen Tauschungen, n.' [The filled (divided) distance is always over- estimated, never underestimated, when compared with the empty ; cases of underestimation observed under certain circumstances (James's illu- sion) have nothing to do with the motive to illusion as such, but depend upon secondary criteria (timidity, endeavour after ease of movement). Various modifications of the original experiments are described ; their results confirm the author's theory.] E. Ackerknecht. ' Zur Konzen- trationsfahigkeit des Traumenden.' [A definition of the thing-in-itself formulated during a dream.] Literaturbericht. Berichtigung. Bd. xiii.. Heft 1. M. Radakovic. ' Ueber eine besondere Klasse abstrakter Begriffe.' [Analyses the process of thought involved in the conception -of limiting values in mathematics. The concepts of the straight line, and of the empty space of physics, lead to the following definition : limiting concepts are abstract concepts, which are obtained in accordance with certain (specified) rules from the consideration of a quantity of infinitely numerous objects, arranged in a definitely ordered series.] V. G-men- berg. ' Ueber die scheinbare Yerschiebung zwischen zwei verschieden- farbigen Flachen im durchfallenden diffusen Lichte.' [Let two differently but uniformly coloured surfaces be set at such a distance from the source of light that they appear to lie in the same plane. If the intensity of illumination here be taken as 1, then with intensities of 2. 3, 4 ... the colour lying towards the red end of the spectrum advances as far before the colour lying towards the blue end as, conversely, the blue advances and the red recedes if the intensity of illumination is reduced to i, ^, {.] V. Benussi. ' Experimentelles iiber Vorstellungsinadaquatheit. I. Das Erfassen gestaltmehrdeutiger Komplexe.' [It has been shown- that, when we apprehend certain complexes of objects of sensation (points or lines the resulting inadequacy of the idea of form optical illusion) is conditioned upon the formation of this form-idea itself, and not simply upon the spatial arrangement or the simultaneous observation of the objects of sensation. In view of Schumann's theory of the optical illu- sions, the question then arises : given the unitary ideation of a complex of objects of sensation which is constant, observed in all its components,
