Ray L. Birdwhistell's extraordinarily weird Microcultural Incidents in Ten Zoos (1969, 34 min.) provides the stunning centerpiece for this Chicago Filmmakers program of experimental science films. Not made as an art film, this record of Birdwhistell's lecture-demonstration at an anthropology convention has a long-standing underground reputation for its obvious affinities with the structural and participatory cinema then emerging. Birdwhistell analyzes footage of visitors in ten zoos around the world, often slowing it down, to reveal the cultural differences in body language: an English father tries to communicate with the animals by talking while an Italian boy makes contact with expressive gestures. The filmmaker acknowledges the possibility of observer bias and seems to have his own interests (“pelvic thrusts,” for example), but there's something wonderfully crazed about his combination of intrusive narration and manipulated imagery. The other superb film on the program, Janie Geiser's Spiral Vessel, is no more easily explained; the filmmaker writes that it “evoke[s] mysteries” rather than facts, and her lush, layered, animated cutouts include science diagrams and grids of holes that suggest a moving tapestry. More austere, even meditative patterns evoke nature's rhythms in Jim Trainor's Plants (1994) and the movement of machines in Michael Johnsen's Oscillo-Recordings. Jeanne Liotta uses footage from found instructional films in her fascinating Bees and Ears and What Makes Day and Night (both 1998), though they can't hold a candle to Birdwhistell. Also showing: Jean Painleve's The Vampire Bat (1945), Luis Recoder's Available Light (06.28.99), Julie Murray's Micromoth, David Sherman's Studies in Hypnosis, and Bradley Eros's Explaining Matter Backwards.