Man is predominantly a visual animal. To him seeing is believing,--a saying which in canine parlance might readily become smelling is believing. We teach by illustrations, models, and object-lessons, and reduce complex relations to the curves of the graphic method, to bring home and impress our statements. Our every-day language, as well as the imagery of poetry, abounds in metaphors and similes appealing to images which the eye has taught us to appreciate. The eye is also the medium of impressions of æsthetic as well as of intellectual value; and one grand division of art is lost to those who cannot see. The eye, too, forms the centre of emotional expression, and reveals to our fellow-men the subtile variations in mood and passion, as it is to the physician a delicate index of our well-being. There are reasons for believing that it was the function of sight as a distance-sense that led to its supremacy in the lives of our primitive ancestors. Whatever its origin, the growth of civilization has served to develop this eye-mindedness of the race, and to increase and diversify the modes of its cultivation. The eye, thus constantly stimulated in waking life, and attracting to its sensations the focus of attention, possessing, as it does, in the retinal fovea a special and unique aid to concentrative attention, does not yield up its supremacy in the world of dreams. The visual centres subside but slowly from their day's stimulation; and the rich stock of images which these centres have stored up is completely at the service of the fancy that guides our dreams. Indeed, the dream itself is spoken of as a vision. Though, as a race, we are eye-minded, individually we differ much with regard to the rôle that sight plays in our psychic life. In one direction a good index of its importance is to be found in the perfection of the visualizing faculty, of which Mr. Galton has given an interesting account. He asked various persons to describe, amongst other things, the vividness of their mental picture when calling to mind the morning's breakfast-table. To some the mental scene was as clear and as natural as reality, lacking none of the details of form or color; to others the resulting mental image was tolerably distinct, with the conspicuous features well brought out, but the rest dim and ill-defined; while a third group could only piece together a very vague, fragmentary, and unreliable series of images, with no distinct or constant picture.