This journal provides immediate access to some articles. Volume 268(1469); April 22, 2001 Maternal androgens in black-headed gull (Larus ridibundus) eggs: consequences for chick development. PMCID: PMC1088678 Asymmetrical crossing barriers in angiosperms. PMCID: PMC1088681 A comparative test of a theory for the evolution of anisogamy. PMCID: PMC1088683 | ||