Thoreau writes in his journal:
After some rain yesterday and in the night, there was a little more snow, and the ground is still covered. I am surprised to find Walden still closed since Sunday night, notwithstanding the warm weather since it skimmed over, and that Goose Pond bears, though covered with slosh; but ice under water is slow to thaw. it does not break up so soon as you would expect. Walking over it, I thought I saw an old glove on the ice or slosh, but, approaching, found it to be a bull-frog, flat on its belly with its legs stretched out…I found it to be alive, though it could only partially open its eyes…It was evidently nearly chilled to death and could not jump, though there was then no freezing. I looked round a good while and finally found a hole to put it into, squeezing it through . . .