xviii RESEARCHES ON IRRITABILITY OF PLANTS 

 CHAPTER XXV 



EFFECT OF TEMPERATURE ON RHYTHMIC PULSATION 

 OF DESMODIUM GYRANS 



PAGE 



Effect of lowering of temperature on rhythmic pulsation of cardiac 

 tissue — Similar effect on the pulsation of Desmodium — 

 Increase of systolic limit during cooling — Minimum tempera- 

 ture for arrest of pulsation — Arrest by cooling and subsequent 

 revival by warming — Increase of diastolic limit during 

 warming — Effect of rise of temperature on the pulsation of 

 frog's heart — Similar effect on the pulsation of Desmodium — 

 Effect of rise above and return to normal temperature — 

 Diminution of systolic contraction during rise of temperature 

 — Increase of systolic contraction during fall of temperature — 

 Permanent arrest due to heat-rigor . . . . . 323 



CHAPTER XXVI 



EFFECT OF CHEMICAL AGENTS ON THE AUTOMATIC 

 PULSATION OF DESMODIUM GYRANS 



Application of gaseous or liquid reagents — Modifying influence of 

 tonic condition of specimen, strength, and duration of appli- 

 cation — Effect of sugar solution — -Effect of alcohol — Action 

 of carbonic-acid gas — Effects of anaesthetics, ether, and chloro- 

 form — Action of carbon disulphide — Effect of copper sul- 

 phate solution — Effect of potassium cyanide solution — Anta- 

 gonistic actions of acids and alkalis on the pulsations of 

 the heart and of Desmodium — Similarities of reaction in 

 rhythmic tissues animal and vegetal ..... 332 



CHAPTER XXVII 



GENERAL SURVEY . . . 342 



Classified List of Experiments ..... 361 



Index .......... 369 



