Contents

12 June 2009
Vol 324, Issue 5933

About The Cover

Cover image expansion

COVER The flight path of a maple seed visualized in a composite multiflash photograph. Autorotating seeds slow their descent by exploiting the low pressure generated by a vortex that forms at the leading edge of their spinning wing. A similar leading-edge vortex also elevates the lift of insect, bat, and hummingbird wings. See page 1438 Photo: David Lentink