Through the study of dream series occurring in a single night, obtained in clinical and experimental situations, two broad patterns are described. In the first, dreams progress in a sequence in which each dream solution acts as a 'night residue' for the next dream. There is progressive tension discharge and regression in keeping with Freud's observation that in a series of dreams the impulse becomes bolder and less disguised. In the second pattern each dream repetitiously restates the same problem with little or no progression. It is as if the day residue, in the form of an unresolved problem, continued to dominate and guide the dreams to repeat themselves. The writers suggest that dream series which are sequential point to an ego better able to cope with current stresses with a fuller solutional range. A repetitive pattern would suggest an ego whose current integrative capacity is being taxed and whose range of possible solutions is limited.