Spier, an institution for 25 years (Caldecott for Noah's Ark, 1978), can probably do no wrong. Dreams is to all intents and purposes a wordless picture book; the entire text, appearing on the penultimate page, reads ". . .and the next time you gaze at the sky: dream dreams!" Two children spend the afternoon gazing from a flowery meadow at a sky graced with a scattering of birds and insects, a wondrous flight of balloons, and the sort of cumulus clouds that speak to the imagination. Alternate illustrations show the clouds as sculpted by the wind and the pictures seen therein by the children: real and fantastic animals (the sun-gilded seal balances the sun on his nose); knights attacking a dragon with spears of jets and their contrails; an impressionistic picnic; a school of fish mouthing the gay hot-air balloons; thunderous monsters. This imaginative romp is represented in Spier's usual pen and watercolor style, in this case mostly watercolor, and though it is neither as subtle nor as detailed as his best books, it is a great pleasure both as puzzles and as pictures. Librarians will have to cope with Doubleday's practice of putting important, unduplicated illustrations on the endpapers.