in Thoreau’s Journal:

Most leaves are already somewhat faded and withered. Their tints are not so bright. The chestnut leaves already rustle with a great noise as you walk through the woods, as they lie light, firm, and crisp. Now the chestnuts are rattling out. The burs are gaping and showing the plump nuts. They fill the ruts in the road, and are abundant amid the fallen leaves in the midst of the wood. The jays scream, and the red squirrels scold, while you are clubbing and shaking the trees.  Now it is true autumn—all things are crisp & ripe.

in Thoreau’s Journal:

This is the end of the sixth day of glorious weather, which I am tempted to call the finest of the year, so bright and serene the air and such a sheen from the earth, so brilliant the foliage, so pleasantly warm (except, perhaps, this day, which is cooler), too warm for a thick coat — yet not sultry nor oppressive — so ripe the season and our thoughts. Certainly these are the most brilliant days in the year, ushered in, perhaps, by a frosty morning, as this. As a dewy morning in the summer compared with a parched and sultry, languid one, so a frosty morning at this season compared with a merely dry or foggy one. These days you may say the year is ripened like a fruit by frost, and puts on brilliant tints of maturity but not yet of decay. It is not sere and withered as in November. See the heaps of apples in the fields and at the cider-mill, of pumpkins in the fields, and the stacks of cornstalks and the standing corn. Such is the season. 

in Thoreau’s Journal:

The red maples are now red & also yellow & reddening. The white maples are green & silvery also yellowing and blushing— The birch is yellow —the black willow brown. The elms sere brown & thin —the bass bare—the button bush which was so late is already mostly bare except the lower part protected — The swamp wht oak is green with a brownish tinge. The Wht ash turned mulberry The white maples toward Ball’s hill have a burnt white appearance— The white oak a salmon color & also red— Is that scarlet oak rosed?— Huckleberries & blackberries are red.

The leaves are falling…

in Thoreau’s Journal:

The autumnal tints about the pond are now perfect—nothing can exceed the brilliancy of some of the maples which stand by the shore & extend their red banners over the water—why should so many be yellow?  I see the browner yellow of the chestnuts on Pine Hill—  The maples & hickories are a clearer yellow.  Some white oaks are red—  The shrub oaks are bloody enough for a ground—  The red & black oaks are yet green.

in Thoreau’s Journal:

The autumnal tints about the pond are now perfect—nothing can exceed the brilliancy of some of the maples which stand by the shore & extend their red banners over the water—why should so many be yellow?  I see the browner yellow of the chestnuts on Pine Hill—  The maples & hickories are a clearer yellow.  Some white oaks are red—  The shrub oaks are bloody enough for a ground—  The red & black oaks are yet green.

in Thoreau’s Journal:

There is a great difference between this season and a month ago — warm as this happens to be — as between one period of your life and another. A little frost is at the bottom of it.

in Thoreau’s Journal:

I observe too that the ferns of a rich brown (being sere),about swamps, etc., are an important feature. A broad belt of rich brown (and crisp) ferns stands about many a bright maple swamp.

in Thoreau’s Journal:

It is well to find your employment and amusement in simple and homely things. These wear best and yield most. I think I would rather watch the motions of these cows in their pasture for a day, which I now see all headed one way and slowly advancing, – watch them and project their course carefully on a chart, and report all their behavior faithfully, – than wander to Europe or Asia and watch other motions there; for it is only ourselves that we report in either case, and perchance we shall report a more restless and worthless self in the latter case than in the first.

in Thoreau’s Journal:

Now the year itself begins to be ripe….

in Thoreau’s Journal:

Why need I travel to seek a site, and consult the points of the compass? My eyes are south windows, and out of these I command a southern prospect. The eye does the least drudgery of any of the senses. It oftenest escapes to a higher employment. The rest serve and escort and defend it. I attach some superiority, even priority, to this sense. It is the oldest servant in the soul’s household; it images what it imagines, it ideates what it idealizes. Through it idolatry crept in which is a kind of religion. If any joy or grief is to be expressed, the eye is the swift runner that carries the news. In circumspection, double, in fidelity, single, it serves truth always, and carries no false news….

How man serves this sense more than any other!  When he builds a house, he does not forget to put a window in the wall. We see truth. We are children of light. Our destiny is dark. No other sense has so much to do with the future. The body of science will not be complete till every sense has thus ruled our thought and language and action in its turn.

in Thoreau’s Journal:

The leaves of some trees merely wither, turn brown, and drop off at this season, without any conspicuous flush of beauty, while others now first attain to the climax of their beauty.

in Thoreau’s Journal:

Examined an Asclepias Cornuti pod, already opening. As they dry, the pods crack open by the seam along their convex or outer side, revealing the seeds with their silky parachutes, closely packed in an imbricated manner, already right side up, to the number in one instance of 134, as I counted, and again 270. As they lie, they resemble somewhat a round plump fish, with the silk ends exposed at the tail. Children call them fishes. The silk is divided once or twice by the raised partition of the spongy core around which they are arranged. At the top of some more open and drier, is already a little clump of loosened seeds and down two or three inches in diameter, held by the converging tips of the down, like meridians, and just ready to float away when the wind rises.