George Owen Mackie. 20 October 1929—25 August 2023

George Mackie was a comparative physiologist who explored how behaviour can arise from interactions between nerves and excitable epithelia. Reading about colonial marine life as a student at Oxford, he wondered how a colony of individual ‘jellyfish’ could coordinate to perform ‘loop-the-loop’ swimming. This led to studies on a wide range of invertebrates such as ctenophores, glass sponges, hydromedusae and tunicates, all animals where behaviour can be approached at a cellular level and from an evolutionary point of view. Mackie’s training as a neuroanatomist was the key to his many discoveries, of which perhaps best known is the role of non-neural signalling pathways in generating behaviour. This, together with electrical signalling in sponges and dual threshold signalling in the jellyfish Aglantha digitale , are among the many fields that Mackie either initiated or promoted. His ingenuity, patience, persistence, curiosity and independence of thought made him a brilliant innovator. He spent most of his career at the University of Victoria, British Columbia, but retained a lifelong affection for UK and Continental European culture. He and his wife, Gillian, were creative potters and warm and generous hosts. Their five children survive them, all highly innovative in their different fields.