110 ETON NATURE-STUDY 



It is interesting to note the methods by which young climbing 

 plants like the hop and French bean seek to find something to climb 

 up. Place a young hop plant in a pot and do the same with a 

 French bean (in the latter case it is best to sow the bean). When a 

 shoot appears six or eight inches above the ground, its movements 

 may be studied. It will be found that the stems turn in a circle. 

 A complete revolution can easily be timed in these plants. In fact, 

 the actual movement may be watched by placing a collar of white 

 paper on the lower part of the shoot, when the shadow of the moving 

 part will be seen passing across it. While this rotation is going on 

 in the tip, another change will be taking place in the stem, which 

 should not be overlooked, and the student should not fail to observe 

 in which way the two plants twine respectively. Futhermore, he 

 may devise for himself a way of showing that the direction of the 

 twist is not accidental, and that the plant cannot be forced to twine 

 in any other way. Again, the extent of surface that a shoot will 

 explore should be ascertained, and the student should note what 

 happens ultimately if the stem has nothing to climb upon. 



Further, the pea, which climbs by means of tendrils, may be profitably 

 studied. First, the movements which the tendril makes in searching 

 for something to catch hold of, and then its actions on touching a 

 solid body, will seem little short of marvellous. By tickling the 

 tendrils with rods, it is easy to find at what age and in what part 

 the tendrils are most sensitive ; how soon these begin to bend round 

 the rod ; and how long they take to straighten again, if the rod be 

 removed. It should be determined whether the tendril is more 

 sensitive in the sunshine or in the shade ; in damp than in dry air. 

 Again, let the student cover a rod with moist gelatine and note the 

 behaviour of the tendril when it is brought into contact with it. 



Finally, an interesting experiment is, to ascertain with what 



