EAST WIND MELTS THE ICE: A Memoir through the Seasons, by Liza Dalby. University of California Press, 2007, 346 pp., $24.95 (cloth)

"Earthworms twist" — "Prunella flourishes" — "Load up fertilizers" — "Moss glows green." What are these?

Well, in ancient China, around the time of Confucius, the notion took hold that the ruler must honor seasonal change exactly or else he would court disaster. The Chinese in those days (if not now) perceived subtle but vital shifts in the air, water, and earth every five days, so that became the minimal seasonal division (hou). A total of 72 such divisions, then, made up the whole year, by solar reckoning.

By the time of the father of the First Chinese Emperor (259-210 B.C.), each such division had acquired a succinct phrase describing the most notable phenomenon: "east wind melts the ice," "fish jump out of the cracks of the ice," "the otter offers prayers to the fish" (before devouring it), and so forth. So, the phrase "earthworms twist" (to turn themselves into knots deep in the earth) pointed to the five-day period of the winter solstice.