Science: The Pulse of Protoplasm

Most obvious door to the central mysteries of life is protoplasm, the basic stuff of living cells. An intriguing characteristic of all raw protoplasm is its "streaming"—a flow like watery jelly. For some years Dr. William Seifriz, professor of botany at the University of Pennsylvania, has cultured an exceedingly primitive, golden yellow slime mold called Physarum polycephalum, just about the lowest observable form of life. In its streaming he has clocked a major rhythm of about 45 seconds (TIME, Dec. 6, 1937). Rather like a primordial heartbeat, this pulse may be the...

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