The EXPLORER'S NOTEBOOK series brings some of nature's finest and most common treasures into sharp focus for young people. As a set of elementary field guides, it succeeds in giving a child the framework to learn about birds, insects, trees and wildflowers in an active fashion, no small accomplishment in an age of television. The concept is good, although the veteran naturalist may find some annoying flaws in the text and illustrations.

In spite of their apparent simplicity, the booklets are pedagogically sophisticated. Designed to be carried into the field and used, they are organized for easy reference, complete with a short table of contents, a checklist and an anatomical chart. The salient feature is that there is only one species to a page, each including a large illustration, a short text that is clear and concise, and ample space for observations and notes.

Each booklet contains roughly 30 common species, most of which can be found in any suburban and urban environment. Insects contains pictures that are larger than life, which may make it the most compelling of the four to children. The stag beetle and the dung beetle, for example, can instill terror and awe in a young heart, while such species as the two-spotted lady beetle and the big green darner dragonfly evoke beauty, symmetry and complexity. Trees and Wildflowers have less dramatic appeal, but they are sufficient to introduce the curious young naturalist to botany.

Birds includes many species observable to the naked eye. The illustration are adequate, although the coloring is imprecise in places and identification could have been made easier if the birds had been depicted in their usual habitats. Other important diagnostic features are ommited on some birds, such as the song sparrow (which displays a prominent spot on the breast), making positive identification even more difficult. The illustrations are also a bit sexist, showing only the bright plumage of the males and relegating the more subtle female to only a few words in the text. Emphasis is placed on song and individual habits, however, and there is often interesting background information, such as the barn swallow's 600-mile-a-day flight to gather food or the cowbird's habit of laying her eggs in other birds' nests.

This series can provide hours of entertainment for the entire family as well as for the child. After stalking insects on a cool April afternoon. Taylor Griffin, our 9-year-old neighbor, said, "It was hard, but it was fun." His parents echoed his feelings.

These primers offer more than an introduction to rudimentary science. They also have the potential to nurture those enviable qualities of childhood: curiosity and a sense of discovery.