arises. People pass them by too easily saying, "It is imagination," as if imagination were as easily explained as a problem in Euclid, and was not a mystery, and as if every moving picture in the brain did not need such minute investigation as Darwin gave to earthworms. I was asked to believe that giants, armour, hillside and sunny distance so appeared in my brain because I had seen men who might be enlarged to giants, pictures of armour with which they could be clothed by fancy, brass with which the armour could be coloured. Any rocks might be multiplied and enlarged from memory by imagination to form a hillside, and any sky of sunny blue would make my distance. How plausible for a second! How unthinkable after a momentary consideration! I know I could hardly, if you gave me a hundred thousand pictures of heads, by cutting them up and pasting them together, make a fresh face which would appear authentic in its tints and shadows, and it would be a work of infinite labour. But these faces of vision are not still. They move. They have life and expression. The sunlight casts authentic moving shadows on the ground. What is it combines with such miraculous skill the things seen, taking a tint here, a fragment of
