Art Out-of-Doors 
stem, the hickory an elongated oval, the 
sugar-maple a much fuller oval, the white 
birch a very long and slender oval, and the 
oak a figure approaching more nearly to a 
circle. In other cases the form of the head 
is more irregular, as with the silver-maple, 
for instance, the typical shape of which 
would be expressed by a diagram of broken 
outline. But even in such cases this shape 
may easily be imprinted upon the memory, 
and, once imprinted, the pleasure of looking 
upon a new specimen of the tree is greatly 
increased by one’s knowledge of how nearly 
it coincides with the typical form of the 
species to which it belongs, or how far it 
departs from it. 
But a tree’s general outline is by no means 
the only thing which determines its form. 
Its structure is of almost more importance 
than its outline, as this may be greatly af- 
fected by position, accident, or man’s inter- 
ference, while, within very narrow limits, its 
structure must always be the same. Branches 
now droop stiffly like those of the spruce, 
and now gracefully like those of the elm, or 
they spread at right angles as in the cedar of 
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