This volume systematizes biological form and function by treating morphological development of plants and animals—detailing compositional elements, general shapes of organs, cells, leaves, branches, and skeletons—and then surveying physiological differentiation and integration among tissues and systems. It next analyzes laws of multiplication, examining factors that link growth, nutrition, asexual and sexual reproduction, and population change, including implications for human numbers. A set of appendices supplements the main text with focused discussions on topics such as organ substitution in plants, skeletal theory, plant circulation, body-type origins, constitutional units, and the inheritance of functionally-caused modifications.