ConclusionFrom the figures alone we cannot be encouraged in the hope that the large psychiatric hospitals will readily be emptied of their long-stay populations, by whatever means. In Salford, at least, it is a population ever longer-staying, not by any means al old, increasingly difficult to discharge, and dying only slowly. And we replenish it year by year with new patients. We must examine the people concerned to discover what the "need" really is and to make rational provision, but the hospital and social services must work closely together to achieve this.A further paper uses these and other data to estimate future demand for beds (Fryers, 1973 Summary A prospective study has been carried out of placental lactogen levels in pregnancy complicated by diabetes mellitus. The levels were higher than those in normal pregnant subjects; the higher levels were related to increased placental and fetal weight but more closely to the former; and lower levels were found when there was clinical evidence of placental dysfunction. Those patients requiring the largest insulin increment for the control of their diabetes in the pregnancy have placental lactogen levels in the higher range.