The Sensitive Plant is so called from its motions 
imitating the sensibility of animal life. The plants 
of this genus naturally contract themselves in the 
evening, and expand with the morning’s light: and 
they are still more remarkable for shrinking from 
external violehce, and folding up their leaves at the 
mere approach of one’s hand. 
Whence does it happen that the plant, which well 
We name the Sensitive, should move and feel ? 
Whence know her leaves to answer her command, 
And with quick horror fly the neighbouring hand ? 
Prior. 
These are questions which naturalists have not 
yet been able to answer, Darwin asks: “May it 
not be owing to a numbness, or paralysis, consequent 
to too violent irritation, like the fainting of animals 
