108 



TIIK T.KAVKS, 



of the shoots of (he common Barberry offer a familiar instance of 

 the kind (Fig. 29G). The most extraordinary modification of the 

 leaf occurs in the 



301. Fly-traps of Dionsea muscipula, the Venus's Fly-trap of North 



Carolina (which is found only 

 in the vicinity of "Wilming- 

 ton, where it abounds in 

 /vf%^ wet and sandy bogs). Each 



leaf of this most curious plant bears at its summit an append- 

 age (answering, perhaps, to the proper blade), which opens and 

 shuts : fringed with strong bristles or slender teeth on its margin, 

 it bears some resemblance to a steel-trap, and operates much like 

 one. For when open, as it commonly is when the sun shines, 

 no sooner does a fly alight on its surface, and brush against any 

 one of the several long bristles that grow there, than the trap 

 suddeidy closes, often capturing the intruder, pressing it all the 

 harder for its struggles, and commonly depriving it of life. After 

 all movement has ceased within, the trap slowly opens, and is ready 

 for another capture. Why this plant catches insects, we are unable 

 to say ; and as to the mechanism of the movement it is no more and 

 no less explicable than the much slower movements of ordinary 

 leaves in changing their position. 



FIG 297 A plant of Pionaca muscipula, reduced in si; 

 nearly the natural size ; one of them open, the others closed. 



2DS Three of the leaves, of 



