RESPONSE IN THE LIVING AND NON-LIVING.With 117 Illustrations,8vo. 10s. 6d. 1902
PLANT RESPONSE: AS A MEANS OFPHYSIOLOGICAL INVESTIGATION.With 278 Illustrations, 8vo. 21s. 1906
COMPARATIVE ELECTRO-PHYSIOLOGY.A PHYSICO-PHYSIOLOGICAL STUDY.With 406 Illustrations, 8vo. 15s. 1907
RESEARCHES ON IRRITABILITY OFPLANTS. With 190 Illustrations,8vo. 10s. 6d. net 1913
LIFE MOVEMENTS IN PLANTS, VOL. I.With 92 Illustrations, 8vo. 10s. 6d. 1918
Longmans, Green & Co.
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[i]
I have in the present volume dealt with the intricatephenomena of different tropisms. The movements in plantsunder the stimuli of the environment—the twining oftendrils, the effect of temperature, the action of lightinducing movements sometimes towards and at other timesaway from the stimulus, the diametrically opposite responsesof the shoot and the root to the same stimulus of gravity,the day and night positions of organs of plants—these, andmany others present such diversities that it must haveappeared a hopeless endeavour to discover any fundamentalreaction applicable in all cases. It has therefore beencustomary to assume different sensibilities especially evolvedfor the advantage of the plant. But teleological argumentand the use of descriptive phrases, like positiveand negative tropism, offer no real explanation of thephenomena. Thus to quote Pfeffer "When we say that anorgan curves towards a source of illumination, because ofits heliotropic irritability we are simply expressing anascertained fact in a conveniently abbreviated form, withoutexplaining why such curvature is possible or how it isproduced.... Many observers have unfortunately devotedtheir attention to artificially classifying the phenomenonobserved, and have entirely neglected the explanation ofcauses underlying them." He also adds that in regard tothe phenomenon of growth and its variations, an empirical[ii]treatment is all that is possible in the present state of ourknowledge; but deduction from results of experimentalinvestigation "still remains the ideal of physiology, and onlywhen this ideal has been attained, shall we be able toobtain a comprehensive view of the interacting factors atwork in the living organism."
In my previous work on "Plant Response" (1906) Idescribed detailed investigations on irritability of plantswhich I carried out with highly sensitive recorders. Theplant was thus made to tell its own story by means ofits self-made records. The results showed that there isno specific difference in physiological reaction of differentorgans to justify the assumption of positive and negativeirritabilities. A generalisation was obtained which gave acomplete explanation of diverse movements in plants.The results were fully confirmed by an independent methodof inquiry, namely that of electric response, which I havebeen able to elaborate so as to become a very importantmeans of research.
The investigations described in the present volumenot only support the conclusion