THE PLANT IN ACTION. 



265 



itself, and it will sometimes, after many hours, with- 

 draw from one fissure, as if it did not find it satis- 

 factory, and seek another. The.re is something won- 



FIG. 420. 



derfully like instinct in all this. Prof. Gray remarks : 

 " If we watch the tender passion-flowers which show 

 the revolving so well on a sultry day, we may see 

 with wonder that, when a tendril, sweeping hori- 

 zontally, comes round so that its base nears the par- 

 ent-stem, rising above it, it stops short, rises stiffly 

 upright, moves on in this position until it passes ty 

 the stem, then rapidly comes down again to the hori- 

 zontal position, and moves on so until it again ap- 

 proaches and again avoids the impending obstacle." 



Observe the structure and watch the movements 

 of tendrils in pumpkin, squash, gourd, and grape 



