The papers in this volume cluster about the following topics: the location of the zeros of polynomials and other analytic functions; the approximation of analytic functions by polynomials in which the location of zero is restricted (these papers represent some of Polya's most influential work); the behavior of the zeros of successive derivatives; the zeros of functions defined by trigonometric integrals; and the signs of derivatives and their analytic character. The volume also includes a paper that is not about zeros but contains a representation theorem for positive polynomials in several variables.