THE LIVING WORLD 



201 



FIG. 32. 



while young spheroidal aggregations are formed within 

 the parent. 



Some plants, as the well-known sensitive plant, move 

 their leaflets on being touched. Others will move parts 

 of their flowers, either for the purpose of setting seed, or 

 for protection, or for some other reason (as the pimpernel 

 will close its flowers under a clouded sky), or to project 

 their seeds to a considerable distance, as is the case 

 with certain balsams. There are two kinds of plant, 

 however, which are quite 

 exceptional in the move- 

 ments they will effect. The 

 first of these is the sun- 

 dew of the genus Drosera. 

 The upper surfaces of its 

 leaves bear certain hair-like 

 processes which can dis- 

 charge a tenacious fluid. 

 Any insect, settling upon 

 the leaf, is apt to be caught 

 by these processes, which 

 bend over it and bathe it Volvox globator, MUCH MAGNIFIED. 

 in the fluid they distil. Showing ribratile cilia on its sur- 

 The other plant is called face and numerous young con- 

 TT , a /TT \ tained within it. 



venus s ny-trap (-big. 33) 



(Dioncea). Its leaves terminate in two rounded expan- 

 sions, joined by a median hinge, and they bear strong 

 bristles along their margins. When an insect alights on 

 this structure, the two rounded expansions snap sharply 

 together and imprison it. 



Such phenomena are, indeed, different from any to be 

 met with in the non-living world, though they are, of 

 course, nothing to the complex movements of animals. 

 Everybody knows that, as a rule, plants hardly move at 



