xx RESEARCHES ON IRRITABILITY OF PLANTS 



FIGURE PAGE 



38. Staircase response in Mimosa ...... 77 



39. Effect of stimulus in modifying the tonic condition . . 79 



40. Alternating response . . . . . . . .81 



41. Fatigue-decline in frog's muscle . . . . . .81 



42. Different phases in the fatigue reversal in plant ... 83 



43. Fatigue reversal in Mimosa. ...... 83 



44. Effect of sudden darkness on excitability of Mimosa 



45. Abolition of motile excitability of pulvinus by absorption of 86 



water 88 



46. Stimulating action of ozone ...... 90 



47. Effect of CO- on excitability of Mimosa .... 90 



48. Effect of vapour of alcohol ....... 91 



49. Effect of ether ......... 92 



50. Effect of carbon disulphide ...... 93 



51. Effect of coal gas ........ 93 



52. Abolition of excitability under chloroform .... 94 



53. Effect of ammonia ........ 95 



54. Effect of sulphuretted hydrogen ...... 95 



55. Effect of nitrogen dioxide ....... 96 



56. Effect of sulphur dioxide ....... 96 



57. Excitatory effect on Mimosa by sudden cooling or warming . 100 



58. Death-curve of Mimosa ....... 102 



59. Abolition of response to warming or cooling after passing through 



the death-point . . . . . . . .103 



60. Death-curve of Desmodium gyrans . . . . .104 



61. Thermo-mechanical inversion indicating death-point of leaf of 



bean .......... 105 



62. Lowering of death-point under fatigue . . . . .106 



63. Effect of poison in lowering the death-point . . . .106 



64. Latent period of hyoglossus muscle . . . . .109 



65. Simultaneous record of vibrating recorder and exciting tuning 



fork no 



66. Apparatus for determination of latent period of Mimosa . 112 



67. Two successive records exhibiting identity of latent period of 



Mimosa . . . . . . . . .115 



68. Record of latent period of highly excitable Mimosa . .116 



69. Record of latent period with a 200 D.V. recorder . . .117 



70. The same record magnified . . . . . . .118 



71,72. Two records obtained with two different recorders . . 119 



73. Record of latent period of Neptunia . . . . .120 



74. Simultaneous excitation in interposed tract under alternating- 



shock . . . . . . . . . .124 



75. 76. Effect of intensity of stimulus on latent period . . .126 



