Contents

08 July 2005
Vol 309, Issue 5732

About The Cover

Cover image expansion

COVER Scanning electron micrograph of an etched sample of the mineral skeleton of the marine glass sponge (genus Euplectella), showing the laminated silica cement that holds glassy fibers in place. The design principles of this sophisticated, mechanically stable structure are described on page 275. [Image: J. C. Weaver, D. E. Morse, and J. Aizenberg]