Returning to these two great streams of rooks, which pour every evening in converging currents from the north and east upon the wood; why do they do this? Why not go forth to the west, or to the south, where there are hills and meadows and streams in equal number? Why not scatter abroad, and return according to individual caprice? Why, to go still further, do rooks manoeuvre in such immense numbers, and crows fly only in pairs? The simple truth is that birds, like men, have a history. They are unconscious of it, but its accomplished facts affect them still and shape the course of their existence. Without doubt, if we could trace that history back there are good and sufficient reasons why rooks prefer to fly in this particular locality, to the east and to the north. Something may perhaps be learnt by examining the routes along which they fly. The second division--that which goes northwards, after flying little more than a mile in a straight line--passes over Wick Farm, and disperses gradually in the meadows surrounding and extending far below it. The rooks whose nests are placed in the elms of the Warren belong to this division, and, as their trees are the nearest to the great central roosting-place, they are the first to quit the line of march in the morning, descending to feed in the fields around their property. On the other hand, in the evening, as the army streams homewards, they are the last to rise and join the returning host. So that there are often rooks in and about the Warren later in the evening after those whose habitations are farther away have gone by, for, having so short a distance to fly, they put off the movement till the last moment. Before watches became so common a possession, the labouring people used, they say, to note the passage overhead of the rooks in the morning in winter as one of their signs of time, so regular was their appearance; and if the fog hid them, the noise from a thousand black wings and throats could not be missed. If, from the rising ground beyond the Warren or from the downs beyond that, the glance is allowed to travel slowly over the vale northwards, instead of the innumerable meadows which are really there, it will appear to consist of one vast forest. Of the hamlet not far distant there is nothing visible but the white wall of a cottage, perhaps, shining in the sun, or the pale blue smoke curling upwards. This wooded appearance is caused by timber trees standing in the hedgerows, in the copses at the corners of the meadows, and by groups and detached trees in the middle of the fields. Many hedges are full of elms, some have rows of oaks; some meadows have trees growing so thickly in all four hedges as to seem surrounded by a timber wall; one or two have a number of ancient spreading oaks dotted about in the field itself, or standing in rows. But there are not nearly so many trees as there used to be. Numerous hedges have been grubbed to make the fields larger.