Where and what is the Arctic? What animals live there, and how are they distributed? How do they cope with cold in their austere environment, and how can Arctic mammals survive birth when it is 40 degrees below freezing. How can seals dive to a depth of 1000 metres and stay submerged for more than an hour, and how does complete darkness in winter affect the inhabitants of the high Arctic? This book answers these questions and also gives an introduction to the Arctic. It is based on the author's 40 years of experience in the Arctic, its environment and animal life. As this book contains almost 200 illustrations and deals with the entire Arctic animal kingdom, it will be suitable as a textbook for courses in Arctic biology, and also serve specialists in the field. It is a reference book and a source of information about published original literature. Arnoldus Schytte Blix is dr. philos. and professor of physiology. He worked at the Institute of Arctic Biology, at Fairbanks, Alaska from 1976 to 1979 before becoming director of the Department of Arctic Biology at the University of Tromsø in Norway. He has participated in more than 30 expeditions to various parts of the Arctic and four expeditions to the Antarctic. He is currently the chairman of the Nansen Foundation of Norway, and has served as chairman of the Norwegian National Committee on Polar Research. Professor Blix has been a member of two Norwegian Royal Commissions related to polar problems, and has represented Norway on the Scientific Committee for Antarctic Research (SCAR), the International Whaling Commission, European Polar Board, the International Arctic Science Committee (IASC) and numerous other bodies. He has contributed more than 150 articles to international learned journals, mainly on physiological adaptations in Arctic mammals and birds. He is an elected member of both the Norwegian Academy of Science and Letters and of Academia Europaea, and has received the Nansen Award of Norway.