To this reader at least a sub-mushroom setting is a handicap to overcome, and Ruth Krauss' scattered snatches of childlike conversation only increase the risk of preciosity. Most of the way, however, she manages to maintain a precarious balance in her rhyme full of "tittles" (". . . little smile little frown little street little town. . . little fairy little wish little spaghetti little dish. . ."), which marches across the top of each page while Margot Tomes' barefoot toddlers come and go below, carrying props for their exercises in make believe. "Here comes a firefly for when the moon goes off" says one bearing a candle, and another with petals on her head announces "here comes a wild flower! WOOF." There are other comments dropped here and there -- "I'll be the little street and you be the little street cleaner" (the speaker pictured prone, while a companion sweeps him with a broom) or "I wouldn't wish to be spaghetti" -- and it all does take place under a mushroom, to the likely satisfaction of whimsical grownups and children too young to care why.