TRANSACTIONS OF THE BOSE RESEARCH INSTITUTE, CALCUTTA, VOL. II, 1919 LIFE MOVEMENTS IN PLANTS BY SIR JAGADIS CHUNDER BOSE, Kt., M.A., D.Sc., C.S.I., C.I.E., PROFESSOR EMERITUS, PRESIDENCY COLLEGE, DIRECTOR, BOSE RESEARCH INSTITUTE, WITH 128 ILLUSTRATIONS CALCUTTA BENGAL GOVERNMENT PRESS 1919 PUBLISHED BY THE BOSE RESEARCH INSTITUTE, CALCUTTA. WORKS BY THE SAME AUTHOR. RESPONSE IN THE LIVING AND NON-LIVING. With 117 Illustrations, 8vo. 10_s._ 6_d._ 1902 PLANT RESPONSE: AS A MEANS OF PHYSIOLOGICAL INVESTIGATION. With 278 Illustrations, 8vo. 21_s._ 1906 COMPARATIVE ELECTRO-PHYSIOLOGY. A PHYSICO-PHYSIOLOGICAL STUDY. With 406 Illustrations, 8vo. 15_s._ 1907 RESEARCHES ON IRRITABILITY OF PLANTS. With 190 Illustrations, 8vo. 10_s._ 6_d._ _net_ 1913 LIFE MOVEMENTS IN PLANTS, VOL. I. With 92 Illustrations, 8vo. 10_s._ 6_d._ 1918 LONGMANS, GREEN & CO. London, New York, Bombay and Calcutta. PREFACE TO VOLUME II. I have in the present volume dealt with the intricate phenomena of different tropisms. The movements in plants under the stimuli of the environment--the twining of tendrils, the effect of temperature, the action of light inducing movements sometimes towards and at other times away from the stimulus, the diametrically opposite responses of the shoot and the root to the same stimulus of gravity, the day and night positions of organs of plants--these, and many others present such diversities that it must have appeared a hopeless endeavour to discover any fundamental reaction applicable in all cases. It has therefore been customary to assume different sensibilities especially evolved for the advantage of the plant. But teleological argument and the use of descriptive phrases, like positive and negative tropism, offer no real explanation of the phenomena. Thus to quote Pfeffer "When we say that an organ curves towards a source of illumination, because of its heliotropic irritability we are simply expressing an ascertained fact in a conveniently abbreviated form, without explaining why such curvature is possible or how it is produced.... Many observers have unfortunately devoted their attention to artificially classifying the phenomenon observed, and have entirely neglected the explanation of causes underlying them." He also adds that in regard to the phenomenon of growth and its variations, an empirical treatment is all that is possible in the present state of our knowledge; but deduction from results of experimental investigation "still remains the ideal of physiology, and only when this ideal has been attained, shall we be able to obtain a comprehensive view of the interacting factors at work in the living organism."