Now first I see Perla on all parts of the river.

February 22.  

—To Assabet stone bridge and home on river. 

It is a pleasant and warm afternoon, and the snow is melting. Yet the river is still perfectly closed (as it has been for many weeks), both against Merrick’s and in the Assabet, excepting directly under this upper stone bridge and probably at mouth of Loring’s Brook. 

I am surprised that the warm weather within ten days has not caused the river to open at Merrick’s, but it was too thick to be melted. 

Now first, the snow melting and the ice beginning to soften, I see those slender grayish-winged insects creeping with closed wings over the snow-clad ice, — Perla (?) on all parts of the river. Have seen none before, this winter. [From a third of an inch to an inch long; of various sizes, etc. And every warm day afterward. Have in fact four wings.]

Just below this bridge begins an otter track, several days old yet very distinct, which I trace half a mile down the river. 

In the snow less than an inch deep, on the ice, each foot makes a track three inches wide, apparently enlarged in melting. The clear interval, sixteen inches; the length occupied by the four feet, fourteen inches. It looks as if some one had dragged a round timber down the middle of the river a day or two since, which bounced as it went.

There is now a crack running down the middle of the river, and it is slightly elevated there, owing, probably, to the increasing temperature.

H. D. Thoreau, Journal, February 22, 1856

I am surprised that the warm weather within ten days has not caused the river to open at Merrick’s. See January 19, 1856 (“The only open place in the river between Hunt’s Bridge and the railroad bridge is a small space against Merrick’s pasture just below the Rock”); January 24, 1856 (“You may walk anywhere on the river now. Even the open space against Merrick’s, below the Rock, has been closed again”); February 3, 1856 (River still tight at Merrick’s); February 27, 1856 (Am surprised to see how the ice lasts on the river. It but just begins to be open for a foot or two at Merrick’s"); March 2, 1856 ("The opening in the river at Merrick’s is now increased to ten feet in width in some places.") March 12, 1856 ("The last four cold days have closed the river again against Merrick’s,");See also 
A Book of the Seasons,  by Henry Thoreau, Ice-out

I see those slender grayish-winged insects creeping with closed wings over the snow-clad ice.  See  February 18, 1854 ("I  see on ice by the riverside, front of N. Barrett's, very slender insects a third of an inch long, with grayish folded wings reaching far behind and two antennæ.");  March 17, 1858 ("As usual, I have seen for some weeks on the ice these peculiar (perla?) insects with long wings and two tails."); See also A Book of the Seasons, by Henry Thoreau, Signs of the Spring, Perla-like insects appear and Northern Woodlands, Winter's Bug Season (winter stoneflies):

An otter track, several days old . . . which I trace half a mile down the river . . . looks as if some one had dragged a round timber down the middle of the river a day or two since, which bounced as it went. See February 20, 1856 ("See a broad and distinct otter-trail, made last night or yesterday. . . Commonly seven to nine or ten inches wide, and tracks of feet twenty to twenty-four apart; but sometimes there was no track of the feet for twenty-five feet."); March 6, 1856 ("On the rock this side the Leaning Hemlocks, is the track of an otter.”); See also January 30, 1854 ("How retired an otter manages to live! He grows to be four feet long without any mortal getting a glimpse of him”); April 6, 1855 ("it reminds me of an otter, which however I have never seen."); February 20, 1855 (among the quadrupeds of Concord, the otter is "very rare.”) and A Book of the Seasons, by Henry Thoreau, The Otter

February 22. See  A Book of the Seasons,  by Henry Thoreau, February 22

Now first I see those

slender grayish-winged insects

on the snow-clad ice.

A Book of the Seasons, by Henry Thoreau, Now first I see Perla

A Book of the Seasons, by Henry Thoreau

"A book, each page written in its own season, 

out-of-doors, in its own locality."

 ~edited, assembled and rewritten by zphx ©  2009-2026

https://tinyurl.com/hdt-560222