in Thoreau’s Journal:

Paddle from the ash tree to the swimming-place. The further shore is crowded with polygonums (leaves) and pontederia leaves. There seems to have intervened no night. The heat of the day is unabated. You perspire before sunrise. The bullfrogs boom still. The river appears covered with an almost imperceptible blue film. The sun is not yet over the bank. What wealth in a stagnant river! There is music in every sound in the morning atmosphere. As I look up over the bay, I see the reflections of the meadow woods and the Hosmer hill at a distance, the tops of the trees cut off by a slight ripple. Even the fine grasses on the near bank are distinctly reflected. Owing to the reflections of the distant woods and hills, you seem to be paddling into a vast hollow country, doubly novel and interesting. Thus the voyageur is lured onward to fresh pastures.  The melting heat begins again as soon as the sun gets up. My shoes are covered with the reddish seeds of the grass, for I have been walking in the dew. I hear a stake-driver, like a man at his pump, which sucks, — fit sound for our sluggish river. What is the devil’s-needle about? He hovers about a foot above the pads on humming wings thus early, from time to time darting one side as if in pursuit of some invisible prey. Most would suppose the stake-driver the sound of a farmer at a distance at his pump, watering his cattle. It oftener sounds like this than like a stake, but sometimes exactly like a man driving a stake in the meadow.

Mistook a crow blackbird, on a dark-brown rock rising out of the water, for a crow or a bittern, referring it to a greater distance than the actual, by some mirage. It had a boat tail, conspicuous when it flew.

The bullfrogs lie on the very surface of the pads, showing their great yellow throats, color of the yellow breeches of the old school, and protuberant eyes. His whole back out, revealing a vast expanse of belly. His eyes like ranunculus or yellow lily buds, winking from time to time and showing his large dark-bordered tympanum. Imperturbable-looking. His yellow throat swells up like a small moon at a distance over the pads when he croaks. The floating pondweed (Potamogeton natans), with the oblong oval leaf floating on the surface, now in bloom. The yellow water ranunculus still yellows the river in the middle, where shallow, in beds many rods long. It is one of the capillary-leaved plants.