Contents

08 February 1991
Vol 251, Issue 4994

About The Cover

Painted mural of Tikal, Guatemala, illustrating the scale of landscaping and reservoir construction during the Late Classic (A.D. 600 to 900) in portions of the southern Maya Lowlands. Carlos Vierra painted this mural in 1914-15 for the Panama-California Exposition in celebration of the completion of the Panama Canal. See page 658. [With permission of the San Diego Museum of Man, which commissioned the mural; photograph courtesy of Peter D. Harrison]