"A very able "manipulative" mathematician, Fisher enjoys a real mastery in evaluating complicated multiple integrals. In addition, he has a remarkable talent in the most difficult field of approaching problems of empirical research. As a result, his lifework includes a series of valuable contributions giving exact distributions of a variety of statistics, such as the correlation coefficient, the central χ2 with due allowance for degrees of freedom, the noncentral χ2, the quotient of two χ2, etc., etc."