A dark line across the lower meadows marks the course of the brook; it is dark because the snow falling on the water melted. Even now there is a narrow stream unfrozen; though the banks against which it chafes are hard, and will not take the impression of the moorhen’s foot. The water-rats that in summertime played and fed along the margin among the flags are rarely seen in winter. In walking in daylight by the brook now their plunge into the water will not be heard, nor can they be seen travelling at the bottom. They lay up a store of food in a hole away from the stream, generally choosing the banks or higher ground in the withy-beds—places that are not often flooded. Their ordinary holes, which are half, and sometimes quite, under water, will not do for winter; they would be frozen in them, and perhaps their store of food would be spoiled; besides which the floods cause the stream to rise above its banks, and they could not exist under water for weeks together. Still further down, where the wood ends in scattered bushes and withy-beds, the level shore of the shallow mere succeeds. The once soft, oozy ground is now firm; the rushes are frozen stiff, and the ice for some distance out is darkened by the aquatic weeds frozen in it. From here the wood, rising up the slope, comes into view at once—the dark trees, the ash poles, the distant beeches, the white crest of the hill—all still and calm under the moonlight. The level white plain of ice behind stretches away, its real extent concealed by the islands of withy and the dark pines along the distant shore; while elsewhere the ice is not distinguishable from the almost equally level fields that join it. Looking now more closely on the snow, the tracks of hares and rabbits that have crossed and recrossed the ice are visible. In passing close to the withy-beds to return to the wood some branches have to be pushed aside and cause a slight noise. Immediately a crowd of birds rise out of the withies, where they have been roosting, and scatter into the night. They are redwings and thrushes; every withy-bed is full of them. After wheeling about in the air they will presently return—first one, then three or four, and finally the flock, to their roosting-place. It is easy now to walk through the wood without making a noise: there is room to pass between the stoles of ash; and the dead sticks that would have cracked under foot are covered with snow. But be careful how you step; for in some places the snow has fallen upon a mass of leaves filling a swampy hollow. Above there is a thin crust of snow, but under the leaves the oozy ground is still soft.