Crows frequently build in oaks, and unless they are driven away by shot will return to the same neighbourhood the following year. They appear to prefer places near water, and long after the nesting time is past will visit the spot. Small birds will sometimes angrily pursue them through the air as they will hawks. As autumn approaches the swallows congregate on warm afternoons on church steeples; they may be seen whirling round and round in large flocks, and presently settling. I saw a crow go past a steeple a short time since where there was a crowd of swallows, when immediately the whole flock took wing, and circled about the crow, following him for some distance. He made an awkward attempt once to get at some of them, but their swiftness of wing took them far out of his reach. Crows make no friends; rooks, on the contrary, make many, and are often accompanied by several other species of birds. A certain friendliness, too, seems to exist between sparrows, chaffinches, and greenfinches, which are often found together. Some fields are divided into two by a long line of posts and rails, which in time become grey from the lichen growing on the wood. The cuckoos in spring seem to like resting on such rails better than the hedges; and when they are courting, two, or even three, may be sometimes seen on them together. Presently they fly, and are lost sight of behind the trees: but one or other is nearly sure to come back to the rails again after awhile. Cuckoos perch frequently, too, on those solitary upright stones which here and there stand in the midst of the fields. This habit of theirs is quoted by some of the old folks as an additional proof that the cuckoo is only a hawk changed for the time, and unable to forget his old habits, hawks (and owls) perching often on poles or anything upright and detached. The cuckoo flies so much like the hawk, and so resembles it, as at the first glance to be barely distinguishable; but on watching more closely it will be seen that the cuckoo flies straight and level, with a gentle fluttering of the wings, which never seem to come forward, so that in outline he resembles a crescent, the convex side in front. His tail appears longer in proportion, and more pointed; his flight is like that of a very large swallow flying straight. The cuckoo's cry can perhaps be heard farther than the call of any other bird. The heron's power of voice comes nearest: he sails at a great height, and his `quaaack,' drawn out into a harsh screech, may be heard at a long distance. But then he has the advantage of elevation; the cuckoo never rises above the tops of the elms.