RÉAUMUR (René Antoine Ferchault de).Mémoires pour servir à l'histoire des insectes.Paris: de l'imprimerie royale, 1734-1742. - 6 volumes in-4, 246 x 190 : (3 ff.), 654 pp., 50 plates ; (2 ff.), xlvj pp., (1 f.), 514 pp., 40 plates ; (2 ff.), xl, 532 pp, 47 plates; xxxiv pp, (1 f.), 634 pp. wrongly numbered 636, 44 plates; (2 ff.), xliv, 728 pp. 38 plates; (2 ff.), 608 pp. 48 plates. Marbled calf, triple gilt fillet framing the covers, spine ribbed and decorated, gilt arms in the last box, red edges (period binding).in French in the text, 145. First edition and first printing of this seminal work. Réaumur (1683-1757) stood out as one of the greatest naturalists of the 18th century, and his Mémoires pour servir à l'histoire des insectes is undoubtedly his absolute masterpiece. Published from 1734 onwards, this monument to science and sensitivity marks a turning point in the study of the living world. Through meticulous observation and rigorous method, Réaumur reveals, for the first time, the complexity and beauty of the infinitely small. Far from the risky speculations of his contemporaries, he patiently deciphers the behaviour of solitary wasps, dragonflies, hairy bumblebees and processionary caterpillars, describing their habits and customs with almost poetic precision. Every detail, every hypothesis, is verified, tested and described without oversimplification. His approach, both scientific and literary, transforms entomology into a modern discipline. As a mark of its importance, this edition was printed on the royal press. It is illustrated with 6 superb bands, 6 initials and 267 folding plates, engraved mainly by Philippe Simonneau but also by Jean-Baptiste Haussard, Pierre Filloeul and Claude Lucas. A very fine copy in contemporary binding, bearing unidentified arms (eagle displayed gules) on the spine. A very well preserved copy despite some rubbing. Old label of a private library on the top of the spines.