168 



PLANT STUDIES 



(3) Dioncea. — This is one of the most famous and re- 

 markable of fly-catching plants (see Fig. 157). It is found 

 in sandy swamps near AVilmington, North Carolina. The 

 leaf blade is constructed 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 digestion does the 

 trap open again. 



There are certain 

 green plants, not called 

 carnivorous plants, 

 which show the same 

 general habit of sup- 

 plementing their food 

 supply, and so reduc- 

 ing the necessity of 

 food manufacture. 

 The mistletoe is a 

 green plant, growing 

 upon certain trees, from 

 which it obtains some food, supplementing that which it 

 is able to manufacture. 



Fig. 158. Three leaves of Dioncea^ showing 

 the details of the trap in the leaves to right 

 and left, and the central trap in the act of 

 capturing an insect. 



