Contents

01 June 1990
Vol 248, Issue 4959

About The Cover

A graded size series (a twofold difference in mass from the smallest to the largest) of hatchlings from a single clutch of the lizard Sceloporus occidentalis. Large variation in hatchling size was achieved by removing various amounts of yolk from some eggs. Size manipulation, “allometric engineering,” permits an experimental assessment of the effect of hatchling size on locomotor performance. See page 1106. [Photograph by Barry Sinervo]