Growth and Form Development 13 
economy. If this were not so, if all the buds formed and all 
the branches developed in mathematical order, very different 
forms from those with which we are acquainted would result. 
This observation of the natural pruning of buds and twigs 
—withdrawal of water and light killing them and wind storms 
breaking them off — which takes place annually, especially 
as the trees grow older, is important in taking care of trees. 
It teaches that not all dying or dead branchlets, which we 
find on the normally developed tree, indicate any disease 
or abnormal condition. It teaches that pruning is not an 
unnatural but a necessary operation which, if neglected 
and not systematically directed by man, will be done by 
nature in a haphazard manner without ref- 
erence to the wishes of man as to form. 
We learn from this that with the expanding 
crown some parts, the less favorably lighted 
ones, as for instance the interior or the lowest 
portions in a conifer, must eventually be lost, 
and, if we remove them in time, we have it 
in our power to direct the development of 
the tree in form, favoring in the competition 
those parts, which we desire to preserve or 
develop. 
Another fact in the development of the 
crown, which from different points of view 
interests the forester perhaps more than the 
tree-warden is, that every regularly formed 
branch or limb has its origin, its base, in the Fis 5 Diagram 
showing the con- 
very center of the trunk or branch from nection of all 
which it arises, its pith or central portion the pith with 
being in direct connection with the pith of 
the bole or mother branch. The growth of wood which 
takes place annually on the bole or mother branch envelops 
