Note 111 — Chapter IX

Letisimulation, apparently, is not confined to animals; we see that certain plants have acquired a habit that is strikingly like death-feigning. We are apt to regard the plants as being non-sentient, yet there is an abundance of evidence in favor of the doctrine that vegetable life is, to a certain extent, percipient. Darwin has shown conclusively that plant life is as subject to the great law of evolution as animal life; he has also demonstrated, in his observations of insectivorous plants—the sun-dew (Drosera rotundifolia) especially—that these plants recognize at once the presence of foreign bodies when they are brought in contact with their sensitive glands;[A] he has likewise shown that plants, in the phenomenon known as circumnutation, evince a percipient sensitiveness that is as delicate as it is remarkable.[B] Hence, we need not feel surprised when we find, even in a plant, evidences of such a widespread stratagem as letisimulation. The champion death-feigner of the vegetable kingdom is a South American plant, Mimosa pudica. In the United States, where in some localities it has been naturalized, this plant is known as the "sensitive plant." A wild variety, Mimosa strigilosa, is native to some of the Southern States, but is by no means as sensitive as its South American congener. The last-mentioned plant is truly a vegetable wonder. At one moment a bed of soft and vivid green, the next a touch from a finger and, in the twinkling of an eye, it has changed into an unsightly tangle of seemingly dead and withered stems. In this case death-feigning seems absolutely successful as far as protection is concerned; for surely no grass-eating animal would touch this withered stuff, especially if there were other greens in the neighborhood. Death-feigning in plants, and kindred phenomena, are not due, however, to conscious determination; they are, in all probability, simply the result of reflex action.