National Geographic : 1989 Dec
DECEMBER 1989 GEOGRAPHIC NAOAL GAPH MAA Muli: In the Footsteps of Joseph F. Rock The indomitable Joseph F. Rock thrilled a generation of NATIONAL GEOGRAPHIC readers with tales of his explorations of isolated areas of China and Tibet in the 1920s and '30s. Two of his striking accounts were about journeys to Muli, just over the Tibetan border in China's Sichuan Province. There a local king and Tibetan lamas lived beside the route pilgrims took to nearby holy mountains. Early this year Los Angeles lawyer Peter Klika led a group in an attempt to re-create Rock's travels. With the aid of the Chinese Mountaineering Asso ciation they went to Muli, their trucks bouncing over rough logging roads that wound along gorges several thousand feet deep. Rock's account made much of ban dits who held sway over the pilgrimage routes. Klika and his group saw no bandits, but many Tibetans carried rifles-probably to protect their yaks from wild animals. "The monastery has been rebuilt, and the palace's exterior has been restored," reports Burnett Miller, a 65-year-old Sacramento businessman who was on the expedition. Six lamas and several acolytes greeted the group, who were apparently the first Western ers in Muli since Rock's day. The monks served tea, walnuts, pears, and cakes; the visitors gave the monks BURNETTMILLER copies of the GEOGRAPHIC with Rock's articles and photographs of Muli (above). "They were overwhelmed," says Miller. When the Trees Cry, Do the Beetles Hear? Think of thirsty trees crying for help. Then think of insects hearing those cries -and attacking the rel atively defenseless trees. It sounds bizarre, but it may be true. Scientists have recently learned that some plants emit ultrasonic chirps when their vascular systems come under stress from drought; the chirps JOHN M. HUNTER(ABOVE); JOSEPHD. LAVENBURG increase as stress intensifies. Robert A. Haack, a U. S. Forest Service researcher, began to wonder if those chirps -more formally known as ultra sonic acoustic emissions - are heard by bark beetles, insects that attack ailing trees and proliferate during a drought. Haack thought that the emissions might explain how the insects can tell an unhealthy tree from a healthy one. He and his colleagues spent a year re cording the chirps. When they slowed down the recordings to hear the emis sions, "they sounded like bongo drums or popcorn popping," Haack says. The team developed a method of duplicating the chirps and transmitting them through plant tissue. Now they're offering bark beetles a choice between branches with chirps and branches without them. The results are not de finitive, but early data indicate that most insects prefer chirping branches to chirpless ones. Eating Clay Tablets as an Act of Faith In the town of Esquipulas in eastern Guatemala stands a basilica with a carved wooden crucifix known as the Black Christ. The shrine attracts pilgrims, who often buy clay tablets with religious symbols (below). Others buy them in markets in Belize, Hondu ras, El Salvador, and elsewhere in Guatemala (below left). The tablets are meant to be eaten. The practice of earth eating, or geophagy, is widespread in Africa, Mexico, and Central America. Three Michigan geographers, supported by the National Geo graphic Society, studied clay-tablet eating in Cen tral America, where the clay almost invariably comes from pits outside Esquipulas. The geographers found that women are the main consumers of the clay tablets, especial ly during pregnancy to counteract morning sickness and ensure a safe delivery. The team reported that although there may be some nutrition al benefits, eating the clay is essentially an act of faith. They asked one woman: "Do they do you any good?" "Of course they do," she replied. "I have eight children!"