Physiological investigations with Petiole-Pulvinus preparations Mimosa pudica

Abstract

The essential similarity in the responsive reactions of plants and animals which has been demonstrated in my previous works leads us to expect that the study of the simpler phenomena of irritability in the vegetal organism may help in the elucidation of the more complex physiological reactions of the animal. New methods of investigation found successful in the case of plants may, moreover, prove to be equally applicable to the study of reactions in animal tissues. This anticipation has been fully justified, since it was my previous discovery of a method of inducing variation in the conducting power of vegetable tissues that led me to the discovery of a similar means of control of the excitatory impulse in the animal nerve. My investigations on plant-irritability have hitherto been carried out with entire plants. The most suitable plant for these researches is Mimosa pudica , which can be obtained in all parts of the world. An impression unfortunately prevails that the excitatory reaction of this plant can be obtained only in summer and under very favourable circumstances, which has militated against its extensive use in physiological experiments, but this misgiving is without any foundation, for I found no difficulty in demonstrating even the most delicate experiments on Mimosa before the Meeting of the American Association for the Advancement of Science held last Christmas at Philadelphia. The prevailing outside temperature at the time was considerably below the freezing point. With foresight and care it should not be at all difficult to maintain in a hot-house a large number of these plants in a sensitive condition all the year round.