Book excerpt: This compact little book, with more than 120 full-color photographs of the most important trout-stream insects, is a must for all fly fishermen, nationwide. Its crisp text offers basic information on trout-stream entomology and hatching cycles, and gives full information about all the major American mayflies, caddisflies, stoneflies, and midges - their description, behavior, and fishing potential. Each natural fly is shown in its three chief stages - nymph, dun, and spinner - in full color; helpful charts, diagrams, and actual-size silhouettes enhance the text of this invaluable book. (41/4 X 61/4, 100 pages, color photos, illustrations, charts)