388 London Summer WHEN the sun is on the land and dog-roses star the woods, the Londoner turns his thoughts to the countryside. He remembers the Green Line coaches, the railways and the buses that will take him from street to lane and from houses to the open fields. London Transport welcomes this healthy change of heart, adapting routes and services to meet the seasonal demand. In April and May the summer timetables come out. Special routes appear like Green Line 726 to Whipsnade; other routes are extended like bus 14A from Putney to Hampton Court on Sundays.