Distinguished for his pioneer work in the development of ecology and plant physiology in Australia. His publications on ecology include an important book on the vegetation of South Australia, and several papers dealing with the autecology of various species especially as regards their physiological properties, mainly in relation to aridity. He has also contributed very considerably to plant physiology and biochemistry particularly as regards nitrogen and sulphur metabolism. More recent work has been concerned with the metabolism of copper and zinc in plants. His physiological work is distinguished for its breadth as well as for its thorough investigation of stages in metabolism and the recognition of inter-relationships between diverse aspects of metabolism. He has developed especially good analytical methods and used them for this work.