Science: Plant Bites Animal

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The only trouble with Sunday supplement folk tales about deadly trees and monstrous flowers which trap, devour and digest human beings is that they are as untrue as they sound. But it is true that the plant kingdom takes a mild, sporadic revenge on the plant-eating animal kingdom by arranging for certain plants to trap, devour and digest insects, worms, larvae, tiny fish, Crustacea—even birds, mice, frogs. Last week Chicago's Field Museum of Natural History published a booklet, Carnivorous Plants, by Botanist Sophia Prior, describing these plants and their predatory procedures.

The plant called Venus' fly trap, a native of North Carolina, was called by the great Charles Darwin "one of the most wonderful in the world." It has a two-lobed leaf which, while waiting for prey, stands open like a gaping clam shell. From the edges of the leaf two rows of slender spikes project inward like teeth. Two or three sensitive hairs serve as a trigger mechanism. When an insect touches these, the lobes snap together, the spikes meshing to prevent escape. Then the leaf, says Miss Prior, "is converted into a virtual stomach and the glands on the upper surface . . . come into action until all the soft parts of the prey are liquefied."

The common butterwort is one of several plants which exude a sticky substance so that the leaves act like flypaper. "Pitcher plants" grow leaves that collect and hold water in which insects, birds and mice, attracted by toothsome exudates, fragrant smells or bright colors, are drowned. The bladderwort is an underwater plant whose bladders are equipped with elastic, one-way valves. Once a small crustacean or fish has ventured in, he cannot get out.

Such actual plant traps as these have probably inspired the tall tales told by imaginative travelers about others much bigger and much more dreadful. Miss Prior, who dismisses them all as fables, quotes a Dr. Carl Liche who claimed to have seen a woman sacrificed, with horrid ceremony, to a "man-eating tree" in Madagascar. A sojourner in Brazil said he saw a tree which attracted monkeys by means of a peculiar odor, hemmed them in a prison of leaves, dropped their bare bones after three days. Centuries ago a very tall tale popped up about a gigantic Death Flower on a South Pacific island which lured human victims inside its fragrant cavern, put them pleasantly to sleep, destroyed them with acid.