168 



PLANT STUDIES 



>ll; 



(3) DiniKi'ii. — Tins is one of the most famous and re- 

 markable of tiy-catcliino- plants (see Fig. 157). It is fdund 

 only in swamps near Wilmington, Xortli Carolina. The 

 leaf blade is constrnctod like a steel trap, the two halves 

 snapping together, and the marginal bristles interlocking 

 like the teeth of a trap (see Fig. 158). A few sensitive 

 hairs, like feelers, are 

 developed on the leaf 

 surface, and when one 

 of these is touched by 

 a small flying or hover- 

 ing insect, the trap 

 snaps shut and the in- 

 sect is caught. Only 

 after digestidu does the 

 trap ojien again. 



There nix- (.'ertain 

 green plants, not called 

 carnivorous jilants, 

 which show the same 

 general habit of sup- 

 plementing their food 

 supplv, and so reduc- 

 ing the necessity of 

 food nianu f a(' turc . 

 The mistletdc is a 

 green plant, gi-owing 

 upon certain trees, from 



which it obtains some food, supplementing that which it 

 is able to manufacture. 



In rich soil, the organized products of the decaying 

 bodies of plants and animals are ofteix alisorl)ed by ordinary 

 green plants, and so a certain amount of ready-made food 

 is obtained. 



..iS^P^^ij^ 



Fig. 158. Three leaves of Dioiia'O, sliowiii^ 

 tile details of thr trap in tlir leaves tn ri^ht 

 anil left, ami tlir central trap iu the aet of 

 capturing an insect. 



