106 NATURE-STUDY LESSONS. 



46. Discover how the twigs are enabled to support the 

 leaves. 



47. Try to discover how twigs are able to resist gusts 



of wind. 



Tie a piece of twine to a weight such that the cord will break when an 

 attempt is made to lift the weight with a jerk. Then attach the same 

 string to the weight by means of an elastic band and by a jerk, even more 

 vigorous than before, raise the weight. The string remains unbroken. 



48. Explain why the string does not break when the 

 rubber band is used. Apply the knowledge gained to 

 answer No. 47. 



XXVII.-THE APPLE TWIG, 



Observe the apple-tree in winter or early spring. Compare its twigs 

 with those of other trees as to shape, size, firmness and direction of growth. 

 Collect several twigs ; compare their form and markings. Develop the 

 buds on some of them by keeping their cut ends in watei in a, place where 

 the water will not freeze. Keep the others dry for comparison later. 



1. («) Observe the rings on the main branch ; also on 



the twigs. 

 (d) Infer the cause of these rings. 



(c) Note the number of times these rings occur on 



the branch or twig and calculate its age. 



2. Compare branches of different ages. 



3. (a) Select a branch showing two years' growth. 



(d) Observe the difference in the markings of the 



two years' growth, and discover, if possible, 

 the cause of the difference. 



4. («) Examine the terminal bud. 

 (6) Observe the bud unfold. 

 (c) Note its contents. 



5. As the twig lengthens observe the position of the 

 leaves. 



6. Compare new buds forming in the axils of the 

 leaves with older buds. 



