. Animal behaviour. Animals behavior. THE BEHAVIOUR OF PLANTS 27 delicate spines, the slightest touch on any one of which causes the two halves of the specially modified leaf-end to fold inwards on the midrib as a hinge. The transmission of impulse is more rapid, the trap closing in a few seconds ; and electric currents have been observed to accompany the change. Tooth- like spines at the edge of the trap interlock, and serve to prevent the escape of small insects, while short-stalked purple glands secrete an acid digestive juice. Division of labour has been carried further ; and organic behav
. Animal behaviour. Animals behavior. THE BEHAVIOUR OF PLANTS 27 delicate spines, the slightest touch on any one of which causes the two halves of the specially modified leaf-end to fold inwards on the midrib as a hinge. The transmission of impulse is more rapid, the trap closing in a few seconds ; and electric currents have been observed to accompany the change. Tooth- like spines at the edge of the trap interlock, and serve to prevent the escape of small insects, while short-stalked purple glands secrete an acid digestive juice. Division of labour has been carried further ; and organic behaviour, not less pur- posive, is carried out in a manner even more Fia. 7. Veinis's Fly-trap {Dionaia). Leaf viewed laterally in its ex- panded state. (From Darwin's " Insectivorous ;) In other plants adaptive movements are well known. " Few phenomena have such a peculiar appearance as the movements which occur in the sensitive Oxalis when rain comes on. Not only do the leaflets on which the finest rain-drops fall fold together in a downward direction, but all the neigh- bouring ones perform the same movement, although they have not themselves been shaken by the impact of the falling drops. The movement is continued to the common leaf-stalk bearing the numerous leaflets. This also bends down towards the ground. The rain-drops now slide over the bent leaf-stalk and down over the depressed leaflets, and not a drop remains behind on their delicate ; * The waves of impulse are said to be transmitted along definite lines, and to cause * Kerner, " Natural History of Plants," vol. i., p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Morgan, C. Lloyd (Conwy Lloyd), 1852-1936. London : Arnold
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Keywords: ., bookcentury1900, bookdecade1920, bookpublisherlondo, bookyear1920
