In the annual report of the Chief Medical Officer of the Ministry of Health for 1925 (p. 22) the incidence rates of notifications of pneumonia in four-weekly periods are compared for large geographical groups in England and Wales. These rates show the divergence between the north and north-west and the remainder of the country, and also the fact that the north-west (Lancashire and Cheshire) usually compares badly with the north. During 1923 “in none of the thirteen periods was the rate for the north-west less than 15 per cent, in excess of the all-England rate and in ten it was equal to or greater than the rate for the north.” That these remarks still apply may be seen from the figures for 1930 (Table I). If one compares some of the large Lancashire towns with London the contrast is even greater (Table II). The towns giving the largest number of notifications of pneumonia are Liverpool and Manchester. These towns alone contributed 48 per cent, of the total number of notified cases of pneumonia in Lancashire during 1930. Their combined population forms about 30 per cent, of the total. Great caution is, however, required in drawing deductions from rates of notification of pneumonia, as considerable differences exist between one place and another in the extent to which the obligation to notify is complied with. Mortality rates provide a sounder basis of comparison.