46 



Notwithstanding the original downward 

 vertical determination of the root, and up- 

 ward vertical determination of the stem, 

 the annual vertical growth in elongation 

 of a tree, either upward or downward, is 

 nothing in comparison with the growth of 

 it, which forms angles with a vertical line : 

 that is, out of all the numerous points of 

 elongation of the head of a tree, there is 

 but one which can go vertically upward in 

 continuation of the line of the stem ; and 

 out of all the numerous points of elongation 

 of the root, there is but one which can go 

 vertically downward in continuation of 

 the line of the stem ; and I believe that 

 one ceases to do so very soon. 



If the leader of a tree is killed, the light 

 falling equally from above on many buds 

 a multiplicity of leaders may be developed ; 

 though if one grows more vigorously than 

 the others, by overshadowing them from 

 above with its own side growth, it will force 

 them to grow sideways to the light, and 



