as motile response. The evidence of plant's script now removed beyond any doubt the long-standing error which divided the vegetable world into 'sensitive' and 'insensitive.' There remained, however, the question of nervous impulse in plants, the discovery of which, though announced by Dr. Bose, ten years ago, did not yet find full acceptance.

Finding that the scope of his investigation has been very much enlarged by the devise of the Resonant Recorder, Dr. Bose proceeded to attack the current view "that there was no transmission of true excitation in Mimosa, the propagated impulse being regarded as merely hydromechanical." This conclusion was based on the experiments of the leading German plant physiologists, Pfeffer and Haverlandt who failed to bring on any variation in the propagated impulse in plants either by scalding or by application of an anaesthetic. Dr. Bose pointed out that, as Pfeffer applied the chloroform to the outer stalk and Haverlandt scalded the outer stem, neither the stimulant nor the anaesthetic reached the nerves. So he, instead of applying the stimulant or the anaesthetic, in the liquid form, to the outer stalk or stem, confined the Mimosa, in a little chamber, and subjected it to the influence of the vapour of the drug. The fumes now penetrated and reached the nerves and the plant was made to record, by its own script, the variations, if any, produced by the drugs. The plant, by its self-made records, showed exultation with alcohol, depression with chloroform, rapid transmission of a shock with the application of heat, and an abolition of the propagated impulse with the application of a deadly poison like potassium cyanide. This variation in the transmitted impulse, under physiological variations, showed that it was not a physical one. This sealed the fate of the hydromechanical theory.

Dr. Bose went further and showed that the impulse is transmitted in both directions along the nerve but not at the same rate. And, by interposing an electric block, he arrested the nervous impulse in a plant in a manner similar to the corresponding arrest in the animal nerve and thereby produced nervous paralysis in plant, such paralysis being afterwards cured by appropriate treatment. "If he had made no other discovery," says the Editor of the Scientific American "Dr. Bose would have earned an enduring reputation in the annals of science. We know very little about paralysis in the human body, and practically nothing about its cause. The nervous system of the higher animals is so complicated, so intricate, that it is hard to understand its derangement. The human nerve dies when isolated. It is killed by the shock of removal, and responds for the moment abnormally and therefore deceptively. But, if we study the simplest kind of a nerve,—and the simplest is that of a plant,—we may hope to understand what occurs when a hand or a foot cannot be made to move. To find out that plants have nerves, to induce paralysis in such nerves and then to cure them—such experiments will lead to discoveries that may ultimately enable physicians to treat more rationally than they do, the various forms of paralysis now regarded as incurable."