A mouse weighs about one ounce, has a heart rate of 700 beats per minute, a gestation period of 21 days, and lives for less than 3 years. A 5-ton elephant has a heart rate of 30 beats per minute, a 22 month gestation period, a slow metabolic rate and lives for 60 years or more. How are these facts related? In this text Christopher McGowan investigates a wide range of size-related phenomena, from the gliding mechnism of diatoms to blood pressure problems of dinosaurs. A journey through the natural world and life in its various forms.