SCIENCE
Dr. William Seifriz of the University of Pennsylvania lives a quiet bachelor's life in Chester Springs, collects old Italian bronze and French porcelain, permits no telephone in his house. At his ground-floor laboratory in Philadelphia he good-humoredly allows an impertinent squirrel to come in by the window, make off with chocolate bars and filter paper. Squirrels, however, are not Dr. Seifriz' favorite pets. On a far greater favorite of his he last week performed an experiment with extraordinary results.
Slime molds are among the most primitive of living things. Six years ago...