The book "Animal Aggregations" by W. C. Allee is a comprehensive study of the physiological and behavioral effects of crowding on animals, particularly in loosely integrated groups or "animal aggregations." Allee aims to investigate the ecological and physiological implications of these aggregations, focusing on their social and subsocial life. The book is structured around the phenomenon of animal aggregations, presenting a series of notes on an unsolved problem rather than a philosophical treatise. Allee's research began in 1911 and has continued intermittently, with significant contributions from graduate students and support from various institutions and foundations. The introduction sets the stage by discussing the historical context of the study, noting that while much attention has been given to organized societies, this book focuses on the physiological effects of crowding in less structured groups. Allee emphasizes the importance of understanding the general physiology of animals for a comprehensive understanding of human sociology and the social traits of other animals. The book also addresses the challenges in defining terms like "society," "community," and "association," and provides a detailed classification of animal aggregations based on physical contact, social instincts, and other factors. Allee's classification includes both accidental and essential aggregations, ranging from simple protozoan colonies to complex insect societies. He discusses the formation and characteristics of various types of aggregations, such as homotypical and heterotypical associations, and the role of social instincts and environmental factors in their development. The book also explores the harmful and beneficial effects of crowding on growth, reproduction, survival, and other physiological processes, providing a balanced view of the complex dynamics within animal aggregations.The book "Animal Aggregations" by W. C. Allee is a comprehensive study of the physiological and behavioral effects of crowding on animals, particularly in loosely integrated groups or "animal aggregations." Allee aims to investigate the ecological and physiological implications of these aggregations, focusing on their social and subsocial life. The book is structured around the phenomenon of animal aggregations, presenting a series of notes on an unsolved problem rather than a philosophical treatise. Allee's research began in 1911 and has continued intermittently, with significant contributions from graduate students and support from various institutions and foundations. The introduction sets the stage by discussing the historical context of the study, noting that while much attention has been given to organized societies, this book focuses on the physiological effects of crowding in less structured groups. Allee emphasizes the importance of understanding the general physiology of animals for a comprehensive understanding of human sociology and the social traits of other animals. The book also addresses the challenges in defining terms like "society," "community," and "association," and provides a detailed classification of animal aggregations based on physical contact, social instincts, and other factors. Allee's classification includes both accidental and essential aggregations, ranging from simple protozoan colonies to complex insect societies. He discusses the formation and characteristics of various types of aggregations, such as homotypical and heterotypical associations, and the role of social instincts and environmental factors in their development. The book also explores the harmful and beneficial effects of crowding on growth, reproduction, survival, and other physiological processes, providing a balanced view of the complex dynamics within animal aggregations.