Once, some five-and-twenty years ago, a sportsman startled a great bird out of the spot where the streams join, and shot it, thinking it was a heron. But seeing that it was no common heron, he had it examined, and it was found to be a bittern, and as such was carefully preserved. It was the last visit of bitterns to the place; even then they were so rare as not to be recognised: now the progress of agriculture has entirely banished them. CHAPTER THIRTEEN. THE WARREN--RABBIT-BURROWS--FERRETS--THE QUARRY--THE FOREST--SQUIRRELS-- DEER--DYING RABBIT--A HAWK. Under the trunks of the great trees the hedges are usually thinner, and need repairing frequently; and so it happens that at the top of the home-field, besides the gap leading into the ash copse, there is another some distance away beneath a mighty oak. By climbing up the mound, and pushing through the brake fern which grows thickly between the bushes, entrance is speedily gained to the wide rolling stretch of open pasture called the Warren. The contrast with the small enclosed meadow just left is very striking. A fresh breeze comes up from the lake, which, though not seen in this particular spot, borders the plain-like field in one part. The ground is not level; it undulates, now sinking into wide hollows, now rising in rounded ridges, and the turf (not mown but grazed) is elastic under the foot, almost like that of the downs in the distance. This rolling surface increases the sense of largeness--of width--because it is seldom possible to see the whole of the field at once. In the hollows the ridges conceal its real extent; on the ridges a corresponding rise yonder suggests another valley. The two rows of tall elms--some hundreds of yards apart--the scattered hawthorn bushes and solitary trees, groups of cattle in the shade, and sheep grazing by the far-away hedge, give the aspect of a wilder park, the more pleasant because of its wildness. Near about the centre, where the land is most level, an unexpected slope goes down into a cuplike depression. This green crater may perhaps have been formed by digging for sand--so long ago that the turf has since grown over smoothly. Standing at the bottom the sides conceal all but the sky overhead. Some few dead leaves of last year, not yet decayed though bleached and brittle, lie here at rest from the winds that swept them over the plain. Silky balls of thistledown come irresolutely rolling over the edge, now this way now that: some rise and float across, some follow the surface and cling awhile to the bennets in the hollow. Pale blue harebells, drooping from their slender stems here and there, meditate with bowed heads, as if full of tender recollections.