It is through the kindness and courtesy of Maj. Joseph Sailer, M. R. C., Chief of Medical Service at the Base Hospital, Camp Wheeler, Georgia, that this paper is presented. Methods of procedure, arrangement of the work and inspiration for a rather monotonous task were all drawn from him by the various ward surgeons who have treated mumps. It is due to him alone — and this cannot be too clearly stated — that a stupid and insignificant disease became interesting. Patients with mumps have occupied almost half of the hospital for three months. An epidemic of such volume raises mumps to the dignity of a disease. Of approximately 18,000 men in the Thirty-First Division, there were 5,756 cases, an incidence of 32 per cent. Every third man in the division, in other words, has had mumps. Of 13,638 total admissions to the hospital to March, 1918, almost one half