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often peaty nature in which plant foods are deficient, especially nitrogen. However, they make up for this deficiency by catching insects and digesting the required nutrients. Adrian Slack, in his book Carnivorous Plants writes, "(some of) these plants manufacture and secrete their own acids and enzymes and the digestive process is remarkably similar to that in the stomachs of higher animals." Let us consider three such plants, asking ourselves as we do so, 'Could such wonderfully complex trapping mechanisms ever have come about by mere chance?'
In his book, The Private Life of Plants, evolutionist David Attenborough begins his introduction with the following words. "Plants can see. They can count and communicate with one another ... Such statements, put baldly, seem almost fanciful not to say exaggerated to the point of falsity." Is there really a plant that can count? Read on!
Life and Death on Venus
The Venus Fly Trap tempts insect visitors to venture onto its two, hinged, kidney-shaped lobes by offering a reward of sweet, sugary nectar. On the inner red surface of each lobe there are usually three small trigger hairs which, when activated, will close the trap. However, one touch of a hair is insufficient to close the trap. It always requires either two touches of a single hair within twenty seconds or two separate hairs within the same period. The two required touches produce a tiny electrical current causing the two jaws to snap together within one third of a second, thereby trapping the insect before escape is possible. The Venus Fly Trap can count up to two! The two touches within twenty seconds has been interpreted as a safety measure against false alarm. If, for example, the trap should be closed by apiece of wind-blown material this would waste 24 hours in the plant's limited work life.
One Way Traffic
The Parrot Pitcher Plant lies horizontally so it cannot rely on gravity to force its prey down into its jaws. Instead, perilous down-pointing hairs line the interior and as the insect progresses into the pitcher it may easily bend these hairs forward parting them and allowing a clear passage further into the tube. As it progresses the hairs behind it spring up and intercross making reversal an impossibility. Collectively these hairs form a perfect valve allowing movement in one direction only. The unfortunate victims tend to accumulate in a solid mass at the rear end of the pitcher.
Rolling in on the Tide
Adrian Slack, an expert on insect-eating plants, believes that in the Bladderworts we have what is "undoubtedly the most sophisticated trapping device to be found amongst the carnivorous plants". The Bladderwort is rootless and on its underwater shoots, small transparent capsules (bladders), often smaller than a pinhead, are attached. Each capsule has a door which is kept tightly shut by the suction caused by the partial vacuum existing inside the bladder. Any minute aquatic creature touching the sensitive trigger hairs causes a slight distortion on the edge of the door so that it no longer fits tightly on its rim. The door is immediately drawn inwards by the suction and the victim is swept into the bladder with the inrush of water. With the vacuum broken, the door swings back to its normal position and "the victim is a prisoner in the bulbous bladder, all within ten to fifteen thousandths of a second". Certain glands start to suck out the water to restore the vacuum, while other glands produce acids and enzymes which slowly digest the helpless creature!
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