12 LABORATORY AND FIELD EXERCISES 



the arrangement of the leaves on a small portion 

 of a single twig. Label all parts correctly. 

 (3) Sketch, in outline merely, a long mature branch. 



Label correctly. 

 3. The plan and development of the tree. 



a. Compare the arrangement of the branches and buds on 



a small tree with those of the branches just studied. 

 Are the branches grouped on the tree trunk as the 

 smaller branches and twigs are grouped on the main 

 axis of a branch ? Compare the tree with the larger 

 branch sketched above. Did these groups of branches 

 on the main trunk arise originally from lateral buds 

 as on the branch studied above ? Why are they 

 called false whorls of branches, instead of true 

 whorls ? Are there smaller branches on the trunk 

 between the false whorls of vigorous branches ? 

 Compare the spruce and the pine in this respect. 

 How do you account for the naked portions of the 

 trunk of the pine between the false whorls of 

 branches ? How do you account for the naked trunk 

 below the lowermost branches ? 



b. Observe the spruce and the pine from a short distance. 



Can you determine the limits of the last season's 

 growth at the apex of a tree ? How many buds 

 grew last season, including the terminal bud and 

 those which produced vigorous lateral branches ? 

 Can you determine the limits of each season's growth 

 along the tree trunk ? Where are the nodes and 

 internodes on the main central axis of the pine or 

 the spruce ? 



c. Sketch the last three or four years' growth at the 



extreme apex of a pine or a spruce. Label the parts 

 correctly. 



