CURRENT LITERATIM

Hokitika Guardian, 24 September 1927, Page 4

CURRENT LITERATIM

PLANT AUTOGRAPHS. At first sight the idea that a turnip has a signature and that a cabbage is able to report its sufferings to an observer may seem fantastic. Yet, on second thoughts, the sceptic lias to admit that there is no reason why they should he incapable of these feats. Every child knows that plants are living organisms, though they are loss complex in structure than animals. They breathe. They feel heat and cold. They must have nourishment—certain kinds are carnivorous. They respond to stimuli, some of them, such as the sensitive plant, and several species of mimosa, very sharply. Many of them close at sunset as though to sleep: All these are commonplace phenomena or every day experience. It is quite natural, then, to suppose that they have other reactions which are invisible to the naked eye, and even through the most powerful microscope. That this is so has been demonstrated by Sir Jagadis Chunder Bose, whoso investigations in plant biology have recently aroused such attention in scientific circles. Sir Jagadis Bose is a member of divers learned societies, and holds the degrees of various British Universities. He lias a seat on the Committee of Intellectual Co-operation of the League of Nations, and is the founder and director of the Institute in Calcutta that bears his name. The fruits of his latest researches are embodied in “ Plant Autographs and their Revelations,” a fascinating book. His first interest was in electro-physics, hut Ire was induced to study the silent life of plants by the considerations already mentioned. Wc are accustomed to regard pi'ants as insensitive, mimosa and a few other '■ sensitive plants,” being thought to he exceptions. The justification for dividing them into these two classes is that while mimosa makes an active movement when touched, the other plants remain, to all appearances, passive and immobile. But would it not be quite logical to assume that the difference is merely oiie of degree, and that all living plants are in some meas-

lire perceptive. Sir Jap';ulis Bose lias devised an extremely delicate apparatus by which the reactions of plants to the stimulus of an electric current are recorded on a screen in graphs. Many of these are reproduced in his hook. hie has obtained some iemarkabl’e results. That plants exhibit fatigue is proved by a. simple experiment. After their normal responses an interval of fifteen minutes is allowed for rest and three normal responses follow. The interval is reduced to ten minutes, and the subsequent responses are weaker, as is evident from the progressively shorter curves. The plant is then given the full period of recuperation, and the longer lines show that it has regained its pristine vigour. Some plants are more susceptible to fatigue than others. It is difficult to imagine anything more stolid and unemotional' than a carrot. Actually it is very excitable, hut pos-1 sesses great stamina. It makes a long j series of uniform responses before signs 1 of weariness arc observed. In this to-j •spent it is the draught horse of the kitchen garden. Celery, on the other hand, tires easily. Iu this we see how human like is plant behaviour. Indeed, in some ways the plant may even he found to he j superhuman. The author realised this i one day when he was taking a record of a mimosa in his laboratory, tie was getting uniform responses, when sud-1 denly there was a depression, for which ! he could not account, as conditions J seemed to he unchanged. On looking! out ot the window, however, he saw! that a wisp of cloud was passing across! the sun. The plant had perceived the slight darkening which lie had not noticed. When tile cloud had gone, the responses recovered their normal' exuberance, as the faithful graph testified. Cold numbs the plant. When the temperature is lowered, a short curve is succeeded bv a straight line, and the effect persists for several responses after the temperature is raised. Tropical plants succumb to cold more readily than those which flourish in

rigorous fI i juntos. A Eucharis lily subjected fur fifteen minutes to a tem-

perature at freezing point gave no responses, that is to say. it was killed. Ilolly and ivy, however, gave a normal response. Flowers, of course, turn towards the sun, but even solid trees periorm gymnastics under its influence. The “ Fraying Pai'm,” of Faridore, is a ease in point. This palm, the trunk ol which was 10 inches in diameter, had been blown from the upright, and had an average inclination of (j() de- ! trees ro the vertical. If very evening, when the temple hells rang, it bowed down its head in adoration. Every morning it had risen again to its maximum inclination, the are described by the head being 15 foot. This palm was the object of worship, which attracted large numbers of pilgrims, and marvellous cures weie ascribed to it. The author’s tests showed that it was throughout the twenty-four hours in a state of continuous movement, which corresponded almost exactly with the changes' of temperature. This phenomenon is by no means rare. In an Africa coco-nut plantation, the trees laid grown slantingly, because of the prevailing winds from the sea. In the morning the nuts were out of reach, hut in the afternoon the ti’eos verv accommodatingly bent down so that they coin’d be picked with ease. The planter was perplexed, but gratified. Plants react readily to drugs. Dilute vapour of alcohol produces ludicrously unsteady responses from which temperance lecturers could point a moral. I

Sulphuretted hydrogen is particularly lethal to the plant which makes a short broken response and then dies. This explains the absence of vegetation in

the vieini ty of copper smelting wbrks. Two examples of poisoning by chloroform are given. With a large dose there is an immediate diminution in sensibility, followed by a violent spasm —and then oblivion. A smaller dose, prolonged in its application, displays to us a pitiful struggle for life. Just as the anxious doctor notes the failing pulse beats of the patient, so we watch on the record the responses becoming fainter and fainter until they cease. Sir Jagadis Bose lias added a new horror to the dinner table. The wheat of which our roll is made may have endured a moment of blind shattering agony as it was ground in the mill. The potatoes suffered the extremities of torture in their lingering death in the saucepan. As we crunch the crisp succulent lettuce must we not spare a thought for the quivering tissues we are rending to pieces alive? This delicious iced melon has perished in stupefying cold to provide us with dessert. Every kitchen is the scene of tragedies unspeakable and innumerable. This hook is engrossing, hut persons of delicate sensibilities will have their enjoyments impaired by it. and vegetarians should on no account read it.