The Eight International Congress on Photobiology and the CoZZoque InternationaZ du Centre NationaZ de Za Recherche Scientifi- que (C.N.R.S.) entitled "Effets bioZogiques et bioconversion du rayonnement soLaire" have been held in Strasbourg (France) on July 20-25, 1980. "TRENDS IN PHOTOBIOLOGY" is a collection of the lectures which were presented during these- two scientific manifesta- tions. This book also contains a summary of several round table discussions, together with "summing-up" reports by experts in the field. Photobiology is a very active, multidisciplinary field of re- search which plays a growing role in modern science. More attention is being given to the beneficial as well as the detrimental effects of sunlight on living organisms, and especially on mankind. Light is a natural and essential "cofactor" of a large number of biological processes. Vision, photosynthesis, photomorphogenesis, photoregulation ... are among the most documented areas of research. On one hand, new technologies are developed which are aimed at understanding the succession of events which take place on a shorter and shorter time scale (down to picoseconds). On the other hand, the relationships between photochemical events and physiological res- ponses are attracting more and more interest.