h the boughs spring irregularly and at various angles, there is a
tendency in all to stoop less and less as they near the top of the tree.
This structure, typified in the simplest possible terms at _c_, Fig.
17., is common to all trees, that I know of, and it gives them a certain
plumy character, and aspect of unity in the hearts of their branches,
which are essential to their beauty. The stem does not merely send off a
wild branch here and there to take its own way, but all the branches
share in one great fountain-like impulse; each has a curve and a path to
take which fills a definite place, and each terminates all its minor
branches at its outer extremity, so as to form a great outer curve,
whose character and proportion are peculiar for each species; that is to
say, the general type or idea of a tree is not as _a_, Fig. 17., but as
_b_, in which, observe, the boughs all carry their minor divisions right
out to the bounding curve; not but that smaller branches, by thousands,
terminate in the heart of the tree, but the idea and main purpose in
every branch are to carry all its child branches well out to the air and
light, and let each of them, however small, take its part in filling the
united flow of the bounding curve, so that the type of each separate
bough is again not _a_ but _b_, Fig. 18.; approximating, that is to
say, so far to the structure of a plant of broccoli as to throw the
great mass of spray and leafage out to a rounded surface; therefore,
beware of getting into a careless habit of drawing boughs with
successive sweeps of the pen or brush, one hanging to the other, as in
Fig. 19. If you look at the tree-boughs in any painting of Wilson's, you
will see this structure, and nearly every other that is to be avoided,
in their intensest types. You will also notice that Wilson never
conceives a tree as a round mass, but flat, as if it had been pressed
and dried. Most people, in drawing pines, seem to fancy, in the same
way, that the boughs come out only on two sides of the trunk, instead of
all round it; always, therefore, take more pains in trying to draw the
boughs of trees that grow _towards_ you, than those that go off to the
sides; anybody can draw the latter, but the foreshortened ones are not
so easy. It will help you in drawing them to observe that in most trees
the ramification of each branch, though not of the tree itself, is more
or less flattened, and approximates, in its position, to the look of a