THE SPUING FLOEA 103 



(2) Buds and growth. Is there a main terminal bud, 



as in the pine, producing a single excurrent 

 trunk, or is the main terminal bud superseded 

 by one or more laterals which produce a sub- 

 division of the trunk above ? How many lateral 

 buds produce strong shoots each season? Consult 

 the growths of the last four or five years on the 

 terminal portions of branches. How many buds 

 remain latent or produce weak lateral twigs 

 each season ? 



(3) Pruning #'*#. Determine the effect of natural 



and artificial pruning on the form of the tree. 

 Do small unsuccessful twigs or shoots continue 

 to form a part of the crown of the tree or is 

 the crown composed wholly of the more vigorous 

 shoots of past seasons ? 



(4) Adju*tmt'ntx t" tie- i-nrirnment by tropisms. Observe 



the position of branches in the upper, middle, and 



lower thirds of the crown. Is the form of the 



branches and their position "with reference to 



the main or to the secondary axes different in 



the above portions of the crown ? Is the response 



mainly to light or to gravity ? Do the positions 



assumed by the branches secure a better light 



exposure for the leaves and a better position for 



the dissemination of fruits and seeds ? 



e. Baric. Compare the bark on the main trunk and its 



branches. Is there a marked difference in color, and 



in smoothness or roughness, between the bark on 



the branches of the upper and middle portions 



of the crown and that of the main trunk and its 



larger subdivisions -? Is the difference such as to 



form a distinctive characteristic of the species under 



