This volume contains the edited transcript of the Second Topical Colloquium based on leads developed at the original conference on the artery and the process of arteriosclerosis (the Lindau Conference of 1970). The first follow-up colloquium on "The Smooth Muscle of the Artery" was held in Heidelberg in 1973. Planning for the present one was undertaken by the editors with Dr. C. Forbes Dewey, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts. The meeting itself was held June, 1976 at the Delaware Water Gap, Pennsy1vani~, under the joint sponsorship of Totts Gap Institute and the Massachusetts Institute of Technology with financial support from the American Heart Association, the Office of Naval Research, and the Smith, Kline and French Company. The objective of the series of meetings, beginning at Lindau has been to examine from an interdisciplinary and international point of view the fundamental physiologic and pathophysiologic processes pertinent to the development of arteriosclerosis.This colloquium sought to examine critically the evidence relating hemodynamic forces to atherogenesis, to reconcile disparate findings and interpretations in so far as possible; and to make a synthesis of the present state of knowledge of the dynamics of arterial flow. Grateful acknowledgement is made for the valuable assistance of Joan Martin and Helen Goodell in the entire editorial process. The editors acknowledge with thanks the secretarial assistance of Moira Martin, Colleen Nagle, Cindy Carter and Pat Ide. Special thanks are due Joy Lowe who executed the entire final manuscript.