During the past years a considerable number of books have been published on atherosclerosis research. Much attention has been focused on the biochemical properties of lipoproteins and the involvement of lipoprotein metabolism in the atherogenic process. The monograph presented here focuses on morphologic studies of atherosclerotic plaque. One chapter deals with the pathobiochemical changes in the arterial wall at the inception of atherosclerosis. Recently the specific role of macro phages in atherogenesis has been the object of much interest. A morphological study of their role and differentiation is the topic of another chapter. This is complemented by a study of lipoprotein receptors on macrophages and smooth muscle cells both in cell culture and in situ, based on electron microscopic investiga- tions. An immunohistological study on the in situ localization promotes our understanding oflipoprotein metabolism in the arterial wall. The morphologic aspects of more advanced lesions are present- ed in studies of collagens and angiogenic processes in the athero- sclerotic vessel wall. Experimental investigations have also been useful for understanding the pathogenetic aspects of atherosclerosis; one crrapter concentrates on the metabolism of fibromuscular and atheromatous plaques in an experimental model. A final chapter deals with transplant arteriopathy and its possible parallels with conventional atherosclerosis. The widespread discussion of athero- genesis is focused on the arterial wall and its morphological alter- ations, emphasizing once again the importance of morphological research for understanding the pathological basis of disease. Borstel and Magdeburg E. VOLLMER and A.