Pollywogs under ice.

December 21. 

December 21, 2017

Walking over the Andromeda Ponds between Walden and Fair Haven, which have only frozen just enough to bear me, I see in springy parts, where the ice is thin, good-sized pollywogs wiggling away, scared by the sound of my steps and cracking of the ice. 

They appear to keep in motion in such muddy pond-holes, where a spring wells up from the bottom till midwinter, if not all winter.

H. D. Thoreau, Journal, December 21, 1857

Walking over the Andromeda Ponds between Walden and Fair Haven.  See December 21, 1856 ("I go across to the cliffs by way of the Andromeda Ponds."); December 21, 1855 ("to Fair Haven Pond. Return by Andromeda Ponds.")

Which have only frozen just enough to bear me. See December 21, 1855 ("I here take to the riverside. The broader places are frozen over, but I do not trust them yet. Fair Haven is entirely frozen over, probably some days.")

I see, where the ice is thin, good-sized pollywogs wiggling away. See March 13, 1855 ("I am surprised to see, not only many pollywogs through the thin ice of the warm ditches, but, in still warmer, stagnant, unfrozen holes in this meadow, half a dozen small frogs, probably Rana palustris.")