25 September 1998
Vol 281, Issue 5385

About The Cover

Cover image expansion

COVER Two eggs of the red abalone with hundreds of sperm cells attached to the envelope surrounding each egg (inner circle, about 175 micrometers in diameter). Sperm are also trapped in the transparent outermost jelly layer. This special issue discusses the latest theories on sex: how it got started, how it works, and who gets it. See the Vacquier 1995 and the special section beginning on p. 1979. [Photo: V. D. Vacquier]