Having expressed the view that pellagra might, like beriberi and scurvy, be caused by a dietary deficiency1 the writer was invited by the Robert M. Thompson Pellagra Commission to visit them at Spartanburg, S. C., for the purpose of investigating this phase of pellagra. Permission to accept this invitation was granted by the War Department, and the invitation was accordingly accepted. During my short stay at Spartanburg the pellagra commission has put all of their very numerous records and observations at my disposal, has made it possible for me to see a very considerable number of cases of pellagra, and has in every way possible endeavored to facilitate and expedite the investigation. In so far as these observations have any value at all, credit therefor should be awarded to the Robert M. Thompson Pellagra Commission, which has rendered the investigation possible. I also desire