I feel greatly privileged having been asked to talk to you here and I want to begin by thanking the organizers for this invitation.
My task of preparing this talk has caused me considerable worry. Obviously, I shall not be able to present here a sound and objective history of embryology over the past 50 years. If nothing else, my great admiration for my close friend Jane Oppenheimer would keep me from being bold enough to step onto her territory, and there have been other serious attempts of an analytical evaluation of embryology during the past half century, e.g. the Nottingham symposium in 1983, published in 1986. What I intend to present here are my personal reflections based on reminiscences over the years during which I had the good fortune of seeing our science develop and of getting to know personally many of the scientists actively involved in the causal analysis of development.