There is an Inca incantation which stated said roughly: "Lord, give me spiritual peace so that I can acquiesce to what I cannot change, give me courage so that I can change what I can change, and give me wisdom so that I can distinguish one from the other. " Obviously, this incantation can be regularly repeated by any gerontologist, since it is very difficult to distinguish aging from the processes which enhance the organism's viability, aging from diseases, and the mechanisms of aging in various species of animals. According to N. Shock, who compiled a valuable bibliography of the works on aging, more than 43,000 works on gerontology have been published in the last decade. Why do we continue to disagree with one another and hold that the most important mechanisms are still largely unknown to us in spite of that flow of information and an enormous number of facts? What is it that we do not know? Could it be that we do not know the sole sacramental fact which can explain everything, such as the hormone of aging, the programmed triggering of a suicide gene, the appearance of a special toxic agent in the axoplasmic flow of substances, and so forth? Goethe once wrote that a scientist most often holds certain parts, but unfortunately he lacks their sacred link.

stimulating introduction to a school of thinking and a body of research that is not widely known or easily accessible to us. His attempt to provide a unify ing theory of sensory receptor mechanisms based on evolutionary principles is unique and imaginative. Among the joys of a career in science is the opportunity to rub shoulders with people of outstanding intellectual power and, with luck, to have the privilege of their friendship. In May of 1979 I visited the U.S.S.R. as a guest lecturer in chemical senses. During the 8 days that I spent in the beautiful city of Leningrad I had the great good fortune to become acquainted with Yakov Abramovich Vinnikov, and we quickly became good friends. A dinner party at his apartment is among the warmest of my memories, and nothing could please me more than to have the opportunity to introduce him in per son to my colleagues in Western Europe, the Americas, Japan, and Australia. That, I am sorry to say, is a most unlikely eventuality. For the time being, introducing his fertile mind through this book is the best I can do."