ancestors were right.

To understand what sort of trees they were from which he got his
inspiration, you must look, not at an average English wood,
perpetually thinned out as the trees arrive at middle age. Still
less must you look at the pines, oaks, beeches, of an English park,
where each tree has had space to develop itself freely into a more or
less rounded form. You must not even look at the tropic forests.
For there, from the immense diversity of forms, twenty varieties of
tree will grow beneath each other, forming a close-packed heap of
boughs and leaves, from the ground to a hundred feet and more aloft.

You should look at the North American forests of social trees--
especially of pines and firs, where trees of one species, crowded
together, and competing with equal advantages for the air and light,
form themselves into one wilderness of straight smooth shafts,
surmounted by a flat sheet of foliage, held up by boughs like the
ribs of a groined roof, while underneath the ground is bare as a
cathedral floor.

You all know, surely, the Hemlock spruce of America; which, while
growing by itself in open ground, is the most wilful and fantastic,
as well as the most graceful, of all the firs; imitating the shape,
not of its kindred, but of an enormous tuft of fern.

Yet if you look at the same tree, when it has struggled long for life
from its youth amid other trees of its own kind and its own age, you
find that the lower boughs have died off from want of light, leaving
not a scar behind. The upper boughs have reached at once the light
and their natural term of years. They are content to live, and
little more. The central trunk no longer sends up each year a fresh
perpendicular shoot to aspire above the rest, but, as weary of
struggling ambition as they are, is content to become more and more
their equal as the years pass by. And this is a law of social forest
trees, which you must bear in mind whenever I speak of the influence
of tree-forms on Gothic architecture.

Such forms as these are rare enough in Europe now.

I never understood how possible, how common they must have been in
medieval Europe, till I saw in the forest of Fontainebleau a few
oaks, like the oak of Charlemagne and the Bouquet du Roi, at whose
age I dare not guess, but whose size and shape showed them to have
once formed part of a continuous wood, the like whereof remains not
in these isles--perhaps not east of the Carpathian mountains.