viii CONTENTS 



SECT. PAGE 



29. The influence of other forms of radiant energy 71 



30. Mechanical stimuli 72 



31. The action of nutrient and poisonous substances 76 



32. Poisonous substances. Acids 77 



33. Carbon dioxide and carbonic acid 78 



34. Alkalies 79 



35. Alkaloids Si 



36. Alcohols ',.... 85 



37. Anaesthetics 86 



38. Metallic poisons 87 



39. Electrical stimuli 88 



40. Constant currents at varying temperatures 92 



41. Alternating ....... 94 



42. Electrolytic action . 95 



43. Conductivity and resistant power , 96 



44. The influence of the direction of electrical currents 99 



CHAPTER IV 

 THEORETICAL AND GENERAL 



45. Analogy between shock-stoppage and muscular contraction . . . . 101 



46. Nerve fibrillae in plants . . . .102 



47. Transmission of stimuli and rate of propagation 103 



48. Passive or active movements by the chloroplastids . . . . . .105 



49. Theories of streaming . . . . . . . . '. .108 



50. Electrical and electro-magnetic theories . . . . ... .109 



51. Surface-tension theory . . . .112 



52. Electro-chemical surface-tension theory ; m . 115 



Summary of results 119 



APPENDIX 

 The electrical conductivity of egg-albumin 123 



INDEX .127 



