150 LEAVES AND BUDS. 



19. Why do not all the buds on a tree branch open in spring ? Why 

 do some buds produce long shoots and others very short ones ? How 

 could you make a short shoot (dwarf shoot) of, say, Beech grow into a 

 long shoot ? 



20. Describe the structure of the winter-bud of one of our trees, and 

 explain what happens in the spring when it expands into a leafy 

 shoot. 



21. Make outline drawings of the leaves and describe the appearance 

 of the bark of any five British trees. Mention the time of flowering 

 in each case. 



22. Sketch, and shortly describe, the leaves of the Oak and Sycamore. 

 How can these two very different shapes of leaves be accounted for ? 



23. What is a stipule ? Describe the stipules of any four British 

 plants, and explain their use in each 



