The confusion in diagnosis which even a cursory survey of the literature on Raynaud's disease shows to exist seems to have a single basis: departure from the criteria stated by Raynaud.1These criteria are: (1) intermittent attacks of changes of color of the acral parts; (2) symmetrical or bilateral involvement; (3) absence of clinical evidence of occlusive lesions of the peripheral arteries, and (4) gangrene or trophic changes, if present, limited in large degree to the skin. To these four criteria laid down by Raynaud we have added a fifth and a sixth: (5) the disease must have been present for a minimal period of two years, and (6) there must be no evidence of disease to which it could be secondary. These additional criteria we have found necessary to exclude the secondary type of vasomotor disturbance. Early in the course of organic disturbance, the vasomotor manifestations may be