168 PHYSIOLOGICAL BOTANY. PART II. 



experiment showed the more flourishing condition of 

 the" provisioned specimens. 



(5.) Sundews. To the above list we may add one 

 more example, taken from a British genus of plants, 

 the Droserse or Sundews, of which three species are 

 natives of this country. The leaves of these plants are 

 furnished on their upper surface with long hairs, tipped 

 with glandular and viscous globules. When an insect 

 settles upon them it is retained by the viscosity of the 

 gland, and in a little while the hairs exhibit a consider- 

 able degree of irritability, by curving inwards, and thus 

 holding it secure. 



(150.) Sensibility. If we do not consider it clearly 

 established that plants are endowed with an irritability 

 strictly analogous to that which exists in animals, then. 

 seems still less reason for supposing them to possess that 

 " sensibility," by which all animals, but more espe- 

 pecially the higher tribes, are so eminently characterized. 

 In them this property resides in their nervous system, 

 to which there appears to be nothing analogous among 

 vegetables. Even in the lower tribes of animals, their 

 nervous system is so little developed, that they may be 

 mutilated and otherwise injured, to an extent which 

 would speedily cause their death, if the intensity of 

 the pain which they felt were at all proportionable to 

 what animals of a higher grade experience under si- 

 milar treatment ; and yet they scarcely appear to suf- 

 fer any inconvenience. If there were no better ar- 

 gument to satisfy us that plants are utterly devoid of 

 sensibility, we have the general consent of mankind, 

 founded on their daily observation, in favour of the 

 non-existence of such a property. The only plausible 

 arguments in support of the probability of plants being 

 endowed with something analogous to a nervous system, 

 rest upon the effects produced on them by different 

 poisons. When corrosive poisons are imbibed into 

 their system, they destroy the tissue much in the same 

 way as in the animal frame ; but when narcotic poi- 

 sons are imbibed, although they kill the plants, they do 



