HAVE PLANTS A NERVOUS SYSTEM ? 



together, exactly like an ordinary rat-trap ! The teeth on 

 the edges of the halves interlock like the teeth of a trap, and 

 the insect is caught and imprisoned. 



Its body is slowly digested away and goes to nourish the 

 plant. The use of the joint in the sensitive hairs can be 

 easily perceived, for when the two halves shut up together, 

 the hairs fold down exactly like the funnel of a river steam- 

 boat when it passes under a bridge. 



The closing of the two halves, which has been well com- 

 pared to shutting up a half-open book, is very quick, as it 

 does not take more than ten to thirty seconds. There is an 

 abundant flow of "gastric juice,""* but the leaf takes a long time 

 to digest its food. It may require three weeks to finish one 

 insect. Moreover, if overfed, it may turn a bilious or dys- 

 peptic yellow colour, and wither or even die. It only shuts 

 for a short time if a grain of sand touches the sensitive hair, 

 and, like Drosera, is not deceived in its food. 



The Dionsea, Drosera, the Sensitive Plant, Mimulus, Bar- 

 berry, and others, all show us clearly that plants somehow or 

 other act as if they were conscious of what they ought to do. 

 In fact, in all these cases, it is scarcely possible to help 

 believing in some sort of rudimentary nervous system. At 

 any rate Wordsworth comes near this belief, for he has 



written : — 



" It is my faith, that every flower that blows 

 Enjoys the air it breathes. " 



352 



