VENUS'S FLY-TRAP. 61 



panded they are ready to act again, so that a leaf 

 has been found to close and re-open alternately, 

 but unsuccessfully, for four times during six days. 

 Closing in this manner, from irritation by inanimate 

 objects, does not, therefore, prevent the lobes from 

 acting vigorously several times, until some suitable 

 prey is caught, and then they remain closed for an 

 indefinite period, or, if they open again at all, remain 

 torpid and insensible for a considerable period. " In 

 four instances leaves after catching insects never re- 

 opened, but began to wither, remaining closed— in 

 one case for fifteeen days over a fly ; in a second, for 

 twenty-four days, though the fly was small ; in a 

 third, for twenty-four days over a woodlouse ; and in 

 a fourth, for thirty-five days over a crane fly. In two 

 instances, in which very small insects had been natu- 

 rally caught, the leaf opened as quickly as if nothing 

 had been caught." 1 Dr. Canby says that the leaves 

 remain closed for a longer period over insects than 

 over meat. 



In all cases where the leaves re-opened, after having 

 remained a long time closed over insects, or meat, or 

 similar substances, they were so torpid during many 

 succeeding days that touching the sensitive filaments 

 was followed by no response whatever. In their 

 native country, where the plants grow with vigour, 



Darwin, " Insectivorous Plants," p. 309. 



