CONTENTS xiii 



depressing, and toxic agents — Phenomenon of accommodation 



Stimulating action of ozone — Effects of carbonic-acid 



gas, vapour of alcohol, ether, carbon disulphide, coal gas, 

 chloroform, ammonia, sulphuretted hydrogen, laughing-gas, 

 nitrogen dioxide, and sulphur dioxide 85 



CHAPTER VIII 



DEATH-SPASM IN PLANTS 



Criterion of the death of plant — Abolition of electric response at 

 death — Mechanical spasm of death — ^Water-bath for uniform 

 rise of temperature — Excitatory effect of sudden cooling or 

 heating — Erection of leaf with rising, and depression of leaf 

 with falling, temperature — Thermo-mechanical inversion 

 at the death-point — Necessity for specification of rate of rise 

 of tfemperature — Death-record of Mimosa — Abolition 

 of response after death-spasm — Constancy of death-point 

 exhibited by different specimens — Death-records of 

 Desmodium gyrans and Vicia Fava — Death-spasm in ordinary 

 plants — ^The electric-spasm of death — Lowering of death- 

 point by fatigue and by poisonous solution .... 98 



CHAPTER IX 



DETERMINATION OF THE LATENT PERIOD 



Difficulties of accurate determination of Latent Period — Advan- 

 tages of Resonant Recorder — Simultaneous tracings of tuning- 

 fork exciter and Resonant Recorder — Automatic stimulation 

 at a definite moment — Identical value of latent period in 

 successive determinations — Accurate measurement of time- 

 interval shorter than .005 second — Latent period little affected 

 by inertia of recorder — Tabular statement of value of different 

 specimens of Mimosa — Effect of season on latent period . 108 



CHAPTER X 



INFLUENCE OF INTENSITY OF STIMULUS, FATIGUE, 

 AND TEMPERATURE ON THE LATENT PERIOD 



Diffuse stimulation under alternating-shock — Effect of intensity 

 of stimulus on Latent Period — Influence of optimum condition 

 — Effect of fatigue — Effect of temperature . . . . 122 



