Having spoken of the emigration of these birds over sea and land, I cannot allow myself to defer mentioning some other birds of smaller size, which have the same natural instinct: although in the case of those which I have already mentioned, their very size and strength would almost seem to invite them to such habits. The quail, which always arrives among us before the crane, is a small bird, which more commonly keeps to the ground than flies aloft. These birds fly in a similar manner to those I have already spoken of, and not without considerable danger to mariners, when they come near the surface of the earth: for it often happens that they settle on the sails of a ship, and that, too, always in the night, in such numbers that the vessel often sink............