CONTENTS xix 



to constant stimulus of light, in : (a) retina — (b) Biophytum — (c) Des- 

 modium — (4) Thermal — Induction of automatism in Biophytum at 

 favourable temperature — (5) Of internal hydrostatic pressure — Absorp- 

 tion of external energy and its absorption by the plant in latent form — 

 True meaning of ' tonic ' condition — Cause of rhythmicity — After-effect, 

 and its relative persistence ......... 295 



CHAPTER XXV 



INFLUENCE OF VARIOUS CHEMICAL REAGENTS ON THE 

 AUTONOMOUS RESPONSE OF DESMODIUM GYRANS 



The recorder and experimental chamber — Absolute measurement of period 

 and amplitude of Desmodiuiu -oscillation — Responsive significance of up 

 and down movements deduced from (a) analogy with response of 

 Mimosa ; (b) test of increased internal hydrostatic pressure — ' Systolic ' 

 contraction and ' diastolic ' expansion of Desmodiuiu pulvinus — Mode of 

 application of chemical reagents — Action of chemical reagents modified 

 by : tonic condition of plants ; strength of solution ; and duration of 

 application — Effect of anaesthetics — Effect of alcohol — Effect of carbonic 

 acid — Effects of ammonia and of carbon disulphide — Effect of copper 

 sulphate solution, either when applied externally, direct on the pulvinus, 

 or internally — Spark-record of Desniodium-pulsation . . . 315 



CHAPTER XXVI 



EFFECTS OF TEMPERATURE ON AUTONOMOUS RESPONSES 



Increase of frequency and diminution of amplitude of pulsation with rising 

 temperature — Converse effect of fall of temperature — Similar effect in 

 cardiac pulsation — Effect of the reduction of temperature to the thermo- 

 tonic minimum — Explanation of diminution of amplitude of pulsation 

 with rise of temperature — Anomalous use of the word ' relaxation ' — 

 Simple versus additive character of individual pulsation . . . 329 



CHAPTER XXVII 



SIMILARITIES OF RHYTHMIC RESPONSE IN VEGETABLE AND 

 ANIMAL TISSUES 



The similarities, in their fundamental characteristics, of rhythmic tissues, 

 animal and vegetable: (1) In responses — (2) In possession of long re- 

 fractory periods — (3) In incapability of tetanus — Theories regarding the 

 causation of heart-beat — The similarities of rhythmic tissues, animal and 

 vegetable, as seen in : (1) The effects of internal hydrostatic pressure — 

 (2) The effects of variation of temperature — (3) The periodic groupings 



a 2 



