xii RESEARCHES ON IRRITABILITY OF PLANTS 

 CHAPTER IV 



TIME-RELATIONS OF THE RESPONSIVE MOVEMENT AND 

 STANDARDISATION OF STIMULUS 



PAGE 



Latent period of Mimosa — Apex time — Rate of responsive move- 

 ment of leaf — Effect of intensity of stimulus, fatigue, and 

 temperature — Periodic dot marker — Time relations of response 

 and recovery — Effect of season — Response of Biophytum — 

 Response of Neptunia — Abitrary distinction between sensi- 

 tive and ordinary plants — Differential response in Mimosa — 

 Response of ordinary plants — Universal sensitiveness of 

 plants — Standardisation of stimulus — Maximal and Minimal 

 Stimuli — Extreme sensitiveness of Mimosa . . . . 35 



CHAPTER V 



THE ADDITIVE EFFECT ; INFLUENCE OF LOAD, TEM- 

 PERATURE, AND INTENSITY OF STIMULUS 



Greater excitatory efficiency of the break-shock — Additive effect 

 of stimulus — Quantitative relation of additive effect — Effect 

 of load — Thermal chamber — Effect of temperature — Effect of 

 increasing intensity of stimulus on response . . . 52 



CHAPTER VI 



VARIOUS TYPES OF RESPONSE 



Necessity of uniform stimulation — The Periodic Starter — The 

 Automatic Exciter — Electrolytic contact-maker — ^The com- 

 plete Response-recorder — The factor of tonicity — Uniform 

 responses — Fatigue under shortened period of rest — Growing 

 fatigue — ^Alternating fatigue — Staircase response — Explana- 

 tion of erection of leaf under continuous stimulation — Fatigue- 

 relaxation in plant and animal — Response under single stimulus 

 and under tetanisation ....... 64 



CHAPTER VII 



EFFECTS OF DIFFERENT GASES ON EXCITABILITY 

 OF MIMOSA 



Induced change of excitability under sudden variation of light — 

 Abolition of excitability by absorption of water — Restoration 

 of excitability by application of glycerine — Stimulating, 



