FURTHER PROBLEMS OF LYMPHOCYTE PRODUCTION

It is nearly five years (Yoffey et al., 1958) since I was privileged to read before this Academy a paper entitled “Some Problems of Lymphocyte Production.” Since then, events have moved rapidly, and some of the questions which were then outstanding have been answered, but many more have arisen in their place. In this period of rapid change, one must be prepared to abandon some longcherished and preconceived notions, and to avoid hasty generalizations about lymphocytes and their functions. The lymphocyte literature abounds in plausible hypotheses and generalizations based upon observations within a single species or on lymphocytes under a special set of experimental conditions. The difficulty with these hypotheses is that once they have become integrated into the literature, they are extraordinarily difficult to eradicate.