INSECTIVOROUS PLANTS. 195 



If either of these filaments is touched, the two 

 lobes fly together instantly, and the stout bristles 

 on the edge of the leaf interlock after the fashion 

 of a steel trap. 



Now when an unwary insect alights on a leaf- 

 trap, which nature has set, it is sure to touch one 

 or more of the sensitive filaments and is caught, 

 and unless it is large and strong it cannot escape. 

 Strong beetles and the stronger flies will force 

 their way out between the bristles, but the weaker 

 ones are held as if in a vice, and are soon envel- 

 oped in a slimy secretion, which at once begins to 

 exude from the inner surface of the trap, and after 

 several days digests all of the soft parts, when the 

 leaf slowly opens, and, if it is still healthy, is now 

 ready for another victim. 



In my experiments, I have found that the Sun- 

 dews digest their prey more quickly than the 

 Dioncea. But I have worked with only culti- 

 vated plants ; it may be different with those 

 growing in their native bogs, which I hope some 

 of my young readers may be able to investi- 

 gate. 



The Pitcher-plant (Sarracenia purpurea) (Fig. 

 51) is another remarkable Flytrap quite common 

 in bogs from New England to Florida. It is a 



