Senior Lecturer in Medical Statistics in the University of Sydney. Distinguished for his studies of Australian mortality, and for his related statistical studies. The current views on the epidemiology of deaf-mutism are largely based on his enquiries in Australia and elsewhere. He has produced important evidence that melanoma is caused by sunlight. He has studied the statistics of laboratory methods, haematological counting, and amoebic surveys in particular. This work has led him to an extensive enquiry into the theory and application of Pearson's X2 test, obtaining new tests of goodness of fit and revealing many interrelations between other tests. He started his career as a pathologist and has subsequently applied mathematical methods in his work to increasing extent.