XIV CONTENTS 



PAGE 



— Method of continuous observation — The Thermocrescent 

 Curve — Determination of absolute rate of growth at different 

 temperatures ......... 34 



CHAPTER V 



EFFECT OF CHEMICAL AGENTS ON GROWTH 



Effect of stimulants — Effect of anaesthetics — Effect of carbonic acid 

 gas — Effect of vapour of ether — Revival of growth by ether — 

 Effect of chloroform — Effects of sulphuretted hydrogen and of 

 ammonium sulphide — Effect of copper sulphate solution — 

 Stimulating action of poison in minute doses .... 43 



CHAPTER VI 



RELATION OF TURGOR AND TENSION TO GROWTH 



Arrest of growth under drought — Revival of growth after irrigation 

 — Effect on growth of change in rate of ascent of sap — Effect of 

 irrigation with cold and with warm water — Effect of positive and 

 negative variation of turgor — Effect of gain or loss of water 

 on motile and growing organs — Change of turgor under directive 

 movement of sap — Effect of artificial increase of internal hydro- 

 static pressure — Effect of external tension . . . .51 



CHAPTER VII 



EFFECT OF ELECTRIC STIMULATION ON GROW^TH 



Similar excitatory reaction under all modes of stimulation — Struc- 

 tural modifications for perception of external stimulation — The 

 Electric Stimulator — Determination of the latent period — Eft'ect 

 of increasing intensity and duration of stimulation — Continuity 

 between incipient and actual contraction — Similarity of excitatory 

 response in pulvinated and in growing organs .... 62 



CHAPTER VIII 



EFFECT OF LIGHT ON GROWTH 



Normal retardation of growth under light — The latent period — 

 Effect of increasing intensity of light — Similarity of effect under 

 continued electric and photic stimulation — After-effect of light in 

 enhancement of growth — Effects of different rays of spectrum — 

 Effect of thermal rays ........ 71 



