THE WINTEK BUDS SHOW EFFECT OF SUNLIGHT 51 



82. Day and night positions of 

 the clover leaf. 



116. WINTER BUDS SHOW WHAT HAS BEEN THE EFFECT 

 OF SUNLIGHT. Buds are borne in the axils of the leaves 

 (86), and the size or vigor of the leaf determines to a large 



extent the size of the bud. 

 Notice that, in most instances, 

 the largest buds are nearest the 

 tip (Fig. 83). If the largest 

 ones are not near the tip, there 

 is some special reason for it. 

 Examine the shoots on trees 

 and bushes. 



117. The largest buds usu- 



start first in spring, and the branches which arise 

 from them have the advantage in the struggle for exis- 

 tence. Plants tend to grow most vigorously from their 

 ends. Observe that only the terminal 

 bud grew in the hickory twig in Fig. 

 60. Every bud has a story to tell of 

 the value of sunlight. 



REVIEW. What is the relation of the plant 

 to sunlight ? Does its form ever depend on its 

 relation to light? In what direction do the tops 

 of plants grow? Where are the most vigorous 

 branches? What is heliotropism? Why are 

 trees sometimes unsymmetrical? Do you know 

 any instances yourself ? What is one way in 

 which plants profit by the climbins 1 habit ? Is 

 there struggle amongst branches ? Explain. 

 Where are leaves borne in reference to light? 

 Where are leaves usually largest ? Do they 

 develop in darkness ? Are leaves borne di- 

 rectly above one another? How may leaves 

 be arranged? Explain what phyllotaxy is. Are 

 leaves always arranged definitely? Explain the 

 arrangement in some plant which is not mentioned in this lesson. 

 What is the "sleep" of leaves? Which surface of the leaf is ex- 

 posed ? What are compass plants ? How do buds show what the 

 effect of sunlight has been? What buds start first in spring? 



