56 NATURE TEACHING. 



thin flexible stems about any convenient sup- 

 port. Make out the direction in which the 

 stem twines, and how the free end of the stem 

 moves in a circle until it meets with some 

 object to twine around. Make similar obser- 

 vations on any other twining plants which can 

 be obtained. 



4. Examine the passion-flower and grape 

 vine and notice the special, delicate side- 

 branches tendrils by which the plant clings 

 to a support. Those of the passion-flower gen- 

 erally twist up in a beautiful manner, forming 

 a spring, after they have caught hold of an ob- 

 ject, whilst before this they stick straight out. 

 Two examples only are mentioned here, but 

 many others will readily be found. 



STRUCTURE OF STEMS. 



1. Examine young and old pieces of the 

 stems of any of the following plants obtainable : 

 hibiscus, rose, mango, samau, cacao, and note, 

 making careful drawings all the parts previ- 

 ously described (p. 46). Cut stems both across 

 and lengthways. Examine the cut ends of any 

 old trees and compare with young plants of the 

 same kind, noting particularly the enormous 

 difference in thickness of the wood. 



2. Examine, in cross and longitudinal 



