504 G. M. STEATTON: the original spatial character of our senses, I feel that they have at least a definite bearing on the problem in so far as persons base their decision directly on the difficulty those born blind have in visually recognising familiar forms and objects, as well as in reacting appropriately in their presence. As to the reactions, enough has been said to show that they are a poor basis for such an argument ; they do not imply that touch and sight are absolutely dissimilar, but only that the localities in one are not yet identified with definite localities in the other. In regard to the visual recognition of objects familiar by touch, the facts become somewhat easier to understand when one has passed through the ordeal with lenses and mirrors. The mere inversion of the field of view may cause a surprising disturbance of discrimination and recognition, especially in its nicer forms ; so that the shape of an object may not be as exactly noticed as before the inversion, and many things plainly in view may be entirely overlooked. I remember looking at an open fire-place, under these circumstances, for some time, without noticing that a large piece of wood had rolled out on the hearth and was filling the room with smoke. The odour was the first effectual warning I had of what had happened. And in walking through a familiar village on a bright moonlight night I was usually unable to recognise my surroundings. And yet the sifting-out of the common space-relations in two sorts of perception so closely akin as upright and inverted vision must be mere child's play in comparison with the detection of the features common to tactual experience and to an absolutely novel spatial order such as that of sight. The very difficulty of analysing the new experience, of selecting points of attack, and of discerning what is significant or what is not, in the infinite confusion of lines and colours this would certainly be sufficient to account for the frequent, though not universal, failure to recognise what is common to both new and old, without our inferring that the new and old have absolutely nothing in common. In this indirect way, by weakening some of the motives for denying an original spatial character to one of these senses, the present experi- ments may possibly have a larger application. But of course primarily they have to do with matters nearer at hand ; with Ihe process by which the different sense-perceptions, whatever may be the ultimate source of their extension, are organised into one harmonious spatial system. The harmony is found to consist in having our experiences meet our expectations. When sight suggests some definite place in the touch-field and the object is