Lois Ehlert, WAITING FOR WINGSLois Ehlert<. , $17 (40pp) ISBN 978-0-15-202608-0

Ehlert (Hands; Market Day) again spreads her creative wings to deliver this inventively designed picture book about caterpillars' metamorphosis into butterflies. Nestled against a verdant spring-garden backdrop formed by the front end paper and opening page, readers will find a small book within the book. On each of the smaller pages, which are artistic extensions of the main background spread, Ehlert unfolds a rhyming text explaining how caterpillars lay eggs and form "a case in which to grow" before "wings unfold; new butterflies are born!" A series of half and full pages show the brilliant butterflies taking wing, flitting among bold cut-paper-collage flowers in vibrant pinks, purples, yellows, reds and oranges. The brief and cheery tone serves as an inviting introduction into a fascinating life cycle. Several closing pages contain detailed information on butterflies, a visual glossary for butterfly and flower identification (including ways of recognizing butterflies by their caterpillar and chrysalis markings) and suggestions for growing a butterfly garden. On the whole, Ehlert soars with a masterful blend of art and natural science. A must for budding lepidopterists. Ages 3-7. (Apr.)