STOPWATCH BOOKS (Silver Burdett: $7.95 each; 25...

STOPWATCH BOOKS (Silver Burdett: $7.95 each; 25 pp., ages 7-10). It would be hard to find a more appealing set of science books than the eight in this series. Their slim 8x8 formats are crisp with color photos, many of them oversized like the one showing a hairy spider as big as a cereal bowl. These volumes are aptly named because children can literally “stop and watch� such phenomena as an unfurling chrysalis or newborn hamsters tinier than match sticks.

“Chicken and egg� (by Christine Back and Jens Olesen, most photos by Bo Jarner) reveals the inside of an egg after nine days incubation, then at 21 days where feathers and big feet show the chick ready to hatch. As in the other books, the left page explains the photo on the right in two styles of print: a bold heading for young readers followed by smaller type with more details for older kids. Then nestled within those words is a simple drawing or photo to further explain its subject. This is visualization at its best and children won’t be the only spellbound observers. Some unscientific adults may be astonished to learn that snails have lungs and that they shoot darts at each other before mating.

At the end of each edition is an easy index alongside a photo summary with the suggestion that readers try to retell the story in their own words. Also included are experiments such as starting your own snail garden or searching for trapped insects in spider webs. “Bean and plant� (by Christine Back, photos by Barrie Watts) shows precisely what grows beneath the soil and then explains how to re-enact the process in a jar. Another note reassures children that store-bought eggs don’t have live babies in them. “Mushroom� (by Watts) cautions against picking and eating unfamiliar plants.

Much creative thought has gone into this series. So, too, have practical considerations: The bindings are sturdy, and their spongeable covers will survive many hands.

THE LITTLE GO-TO-SLEEP BOOK by Juliet Harmer (Atheneum: $10.95; 32 pp.; ages 3-8). A mother lulls her baby to sleep by explaining how animals and bugs settle in for the night. Lovely gouache paintings.