Ecological chemistry.

Discusses the role of chemical compounds synthesized by many plants that has no purpose in their metabolism in a community of interacting plants and animals. Information on the milkweed Asclepias curassavica in Costa Rica which provides an instance of the effectiveness of the secondary substances in repelling animals; Effect of the Danaine butterflies, which ate the poisons in the asclepiads, on blue jays; Forms of mimicry.