This volume represents a collection of selected papers from a symposium of the Division of Colloid and Surface Chemistry held in Chicago during the national meeting of the American Chemical Society, August, 1973. The response was remarkable to this "By Invitation" symposium on Ordered Fluids and Liquid Crystals. The size alone expresses the growth of the field. The number of contributions assembled here, for example, is approximately twice that at each of the two previous American Chemical Society symposia on this subject. Contributions from eleven countries were presented and this volume contains more than this number of papers from abroad. The increased attention to liquid crystals has brought some interesting trends in the kinds of systems, the experimental methods, and the nature of the lahoratories involved. There has, for example, been an impressive increase in the number of academic studies on liquid crystals. The works herewith published also represent an im­ pressive variety of traditional and novel eXperimental techniques for the study of liquid crystals. These include rheology, infrared spec­ troscopy, dielectrics, ultrasonics, pulsed NMR, the Kerr effect, plus thermal and electrical conductivity.