12 NOVEMBER 1948, Page 17

, 4 Swallow Swallow " The year is divided for most

countrymen by the date of the departure of the swallow's, though the division is not abrupt and the date varies a good deal. More obviously, I think, than any other species they cling longest to the South-West Coast. Devon and Cornwall are the scenes of their last flocks, though odd birds may appear elsewhere. This autumn, as a Cornish Rector informs me, he watched a flight of some forty young swallows wheeling and returning to the telegraph wires on November 2nd, a very late date. The birds bred well this year. Even three successive broods have been recorded, and all the young were not ready for a three-thousand-mile flight at the normal date. What happens to these later broods is an old question ; but at least we know—and it is one of the many mysteries of migration—that young birds do not need the guidance of the old. Young cuckoos, for example, usually emigrate in youth bands at a different date from the old birds. They are led by influences never yet discovered, though claims to certain electro-magnetic forces have been dogmatically alleged.