The number of deaths from measles in the County of London for the three months February, March, and April, 1911, was no less than 1,640, a weekly average of 126, constituting about 8 per cent of the total mortality during that period. The greatest mortality occurred in the poorer districts of London amongst children under five years of age. During the same period the total number of deaths from scarlet fever totalled only 29, though the average number of cases under treatment each week at the hospitals of the Metropolitan Asylums Board and at the London Fever Hospitals exceeded 1,000.