THE NATURALIST.

Otago Witness, Issue 2086, 15 February 1894, Page 48

THE NATURALIST.

Marvels of Carnivorous Plants.

Nowhere is the evidence of design in Nature more emphatically set forth than among certain forms of plant life, which, in their various functions, seem to approach so near the animal kingdom that the observer feels that here is some strange plant animal — something that might possibly form a connecting link between the life of animals and plants. In a close study cf these plants we see many evidences of seeming intelligence that are not found in some animals, and bo remarkable are the actions of certain plants that the impression is forced upon us that we are confronted with intelligence, or something strangely akin to it, shown conspicuously in the group which is populaily k. own as carnivorous plant?, or flesh eaters. A familiar example is the little drosera, so common in variona portions of the country. The plant is small and inconspicuous. The first one I ever saw caught my eye by a sudden flash of fiery red light, and kneeling on the damp grass, I fairly caught the little carnivore in the act which has rendered it co famous. Tn&ra were several tender, delicate stalks in the centre, and around about; it, near the ground, four or five singular, round, pad-like objects, about the

\ size of 6maU buttons. Theße were leaves, and their upper surface was covered with reddish tentacles that stood boldly up, each bearing a delicate drop of dew that gleamed and glistened in the dazzling sunlight like a veritable garnet. Across the top of the leaves a long-legged fragile insect lay, caught but a second before, and dying a most terrible death. Five or six of the hairlike tentacles were thrown across its legs and wings, holding it down and pressing its body nearer and nearer to the leaf, while other rich blood-red stalks were in all positions, bending over to encompass the victim. The sight • was a horror in miniature, and reminded me of the actions of an octopus, or devil-fish, as th 6 little cephalopod is commonly called. It has eight sucker-lined arms radiating from a small, bag-shaped body, and eaoh arm has all the sinuosity, all the possibility of motion of a snake, ever undulating, quiveriug, as if with suppressed emotion, while over the entire mass waves and varied shades of colour seem to ebb and flow. When the octopus captures its prey, its snake-like arms envelop the unfortunate, and wherever they touch they cling as in the case of the delicate tentacles of the plant, though in a different way. It was most interesting to watch the immediate effect of irritation upon this little plant. In five or six seconds after a hair or tentacle was

touched it would bend in the direction, and soon others would deflect. If a fly is caugbt, in a short time ali the hairs turn in that direction as though they had eyes and were seeking out the prey. Several hours are required for all the tentacles to cover the object, and then they remain. until all its juices have been absorbed, when they become erect and beautiful again ; a strange contrast to the reeking mass in which they have been involved, now being objects charming to the eye and attractive possibly to insect life as lures. I tried some interesting experiments with these little flesheaters. Dropping a minute bit of fresh meat upon the surface stimulated them to almost immediate activity, and it was evident that the presence of food was imparted to other and distant tentacles, as all began to trend in that direction. Placirg a stone or small pebble upon the plant, the recognition was evident, but slower; the tentacles or armsbent over, but when they discovered the mistake, that there were no choice juices to absorb, they soon withdrew and became erect. The little plant is a living trap. The beauty of the erect tentacles attracts various forms of infect life that find too late their mistake, and are held and literally devoured by this voracious monster. The experiments which have been made with this plant are extremely interesting, showing that a process akin to digestion goes on ; that the secretion of the glands dissolve various objects, as muscle, cartilage, fibrire, &c. Among the remarkable traps of plant life the Venus's fly-trap (Dionrea) is best known. It is a native of America, having been discovered in North Carolina many years ago, and when its peculiarities were described in a paper to a European scientific society it was considered a joke. The plant is found in low, damp place?, lying flat to the ground and throwing out a number of singular leaves, while from the centre rises a delicate flower-stalk. Each leaf constitutes a trap— the tip end being formed of two lobes hinged in the middle and provided with objects which may well b8 termed teeth. When lying in wait, if we may me the term, the leave 3 are open and the teeth exposed. On the surface of the leaf numbers of hair-like objects throw out a secretion which is very attractive to flies and other insects ; in any event they aio found flying about the tempting bait, beirg possibly attracted by some delicate odour, not percsptible to man. Finally a victim alights upon the surface of the trap. A second later it is crushed and held fast, and the terrible jaws do not open again until the entire animal has beeu absorbed. Plants as traps are well represented in the curious pitcher-plants that not only devour their living prey, but entice it in various ways. The odour of many of these is not particularly pleasant, but it evidently exercises a subtle charm over various forms of insect life. The pitcher-plants attract attention at once by their remarkable appearance. As their name sngge3tp, they are pitcher-like growths capable of holding water, and hanging pendant at the end of a leaf, they often sway in the wind, attractive and graceful objects. Some of the tropical pitcher-plants hold half a pint of liquid, and Alfred Wallace mentions in one of his works that upon a certain occasion he was obliged to resort to them for drinking water, finding it very clear and refreshing, although it was half filled with insects. In Borneo the pitcher-plants attain marvellous perfection and size — their beautiful and artistic forms hanging from the foliage in every direction, One found on the summit of the Kini-balou, a lofty peak in north-western Borneo, and known as the Nepenthes rajah, is a magnificent natural vessel, holding upwards of two quarts of water. Another from this country has a pitcher 20in long, the plant alone being about 20ft long. The pitcher is almost invariably half full of water and a mass of dead insects. They are undoubtedly attrac ed by the peculiar odour, are ovei'come by it and intoxicated and, drop in, to become absorbed or digested by this singular plant. A most interesting description could be given of the number and position of the peculiar honey glands that constitute the attractions or lures to the various insects. In one form Dr Hooker counted over 3000 of these glands on a sirjgle square inch, which means a million for the entire plant. Experiments with the pitcher-plants show that they are sensitive to the introduction of food or other matter. Thus if a stone or some inorganic object is introduced there is no response of secretion, but an increase is noticed immediately, when meat, the white of an egg, or some animal matter is introduced. The digestive power of this plant can be realised when it is known that pieces of fibrine weighing sgr or 6gr are entirely dissolved in Jtwo day?. In referring to the action Dr Hooker says: — "It would appear probable that a substance acting as pepsin is given off from the inner wall of the pitcher, I but chiefly after placing animal matter in I the acid fluid ; but whether this active agent flows from the glands or from some tissue in which they are imbedded, I have as yet found no evidence to show." — O. F. Haldeb, in the Californian Illustrated.