THE PLANT AND THE ANIMAL 281 



his senses (regained consciousness). 1 If this is the 

 indication to be followed, then mimosa, the catchfly, etc., 

 are apparently endowed with sensitiveness, because they 

 do respond to different stimuli, be it a prick, or a light 

 touch, a burn, an electric shock, or some chemical action. 

 There are some especially striking cases in which plants 

 do not respond to every stimulus in the same way, but 

 seem to discriminate between them. For instance, 

 contact with nitrogenous organic substances causes 

 quicker movements in the hairs of the sundew, and a 

 more energetic secretion of its digestive juices, than 

 contact with particles of inorganic matter, which cannot 

 serve it as food. Were it an animal we should say that 

 its mouth waters, that it greedily throws itself upon a 

 dainty morsel. 



Granted that the plant is endowed with sensitiveness, 

 can we not deprive it of this property, make it in- 

 sensible to all kinds of stimulus ? Experiment proves 

 that we are actually able to do so ; moreover, that 

 we attain this end by using the same means as when 

 we wish to bring a man into an insensible condition. 

 We can anaesthetise a plant in the same way as we 

 anaesthetise a man before a serious surgical operation. 

 We oblige it to inhale the vapour of ether or chloroform. 

 For this purpose we have only to cover a pot of mimosa 

 with a glass bell, and place a sponge under it filled with 

 ether or chloroform. After remaining a certain length 

 of time under the glass bell the mimosa will lose its 

 capacity for movement. However much stimulated, it 

 will no longer fold its leaflets, but after being exposed 

 again to fresh air, free from noxious vapours, it will 

 regain its sensitiveness, its irritability. In order that 

 this experiment may succeed we must not expose the 



1 We know, however, that the reverse conclusion is not correct. By 

 the action of some poisons we can deprive an animal of the capacity for 

 responding by a movement to stimulation, without at the same time 

 depriving it of the capacity for feeling. 



