Macroscopic plants and animals interact with their environments in what appear to be fundamentally different ways. Animals, especially humans, possess the sophisticated control and co-ordination systems, which regulate their physiology as well as complex patterns of behaviour. Plants, apparently, lack such sophisticated responses, yet both groups are clearly highly successful. Environmental Physiology "crosses the great divide" between animal and plant biology. It looks at the whole-organism responses of animals and plants to light, to pollution and to disease-causing micro-organisms. It goes on to consider how such responses are controlled and co-ordinated, and how information is communicated between individuals in both animals and plants. The scope of the course is broad, extending from the consequences of environmental change on human health to communication between plants. The unifying theme is the central role of physiology in determining a wide range of biological responses, with the overall aim of providing an integrated understanding of the mechanisms by which both animals and plants cope with their environment.