This booklet, together with the following two, -which are well under way and will succeed it at intervals of, we hope, no more than six months, sets the stage for a new editorial enterprise in the field of brain science. The accent is on the functional aspects of brains rather than on their develop ment, hence the title of the series. The central question being how neural activity is related to behavior, there will be, naturally, a wide scatter of sub jects, and Heiligenberg's monograph on electric fish may be considered typ ical of the expected standard deviation from the mean. Deviations in...