The first fact gained from a study of the 1920 occupational case rate is that just as was the case in age incidence there is less variation between the highest and the lowest than in 1918–19. While in the first epidemic the highest occupational rate was five times the lowest, in the second it was only twice the lowest (Chart XXV). But at the extremes of the two charts we see some tendency to an inversion of the order. In 1918–19 those occupied in “retail sales” outdoors showed a low incidence, while in 1920 they were the highest. So also, the incidence in the school group changed from highest in 1918 to lowest in 1920. The incidence in infants increased; that in the office workers decreased. No general conclusions are warranted from these results. In comparing the sex incidence by age groups we have found that females as a rule showed a slightly greater incidence than males. That this is not due fundamentally to occupational differences is suggested by a comparison of the sex incidence in the two epidemics studied. In 1918 the distribution is practically the same in the two sexes in all occupations except “Home,” “Manual Outdoors,” “Retail Sales Indoors,” “Retail Sales Outdoors” (Chart XXVI). In the first the number of males is so small and in the second and fourth the number of females is so small that these cannot justly be compared. The group, “Retail Sales,” consists in 1918–19 of 69 males and 27 females, out of a total distribution in the population of 426 males and 107 females. This is the only occupation that showed a definite higher incidence among the females, and even here the number is too small for accuracy. In 1920 this difference has practically disappeared. _Effect of race stock._—Leichtenstern remarks in his monograph that the reported differences in influenza morbidity among different races, such for instance as European and other nationalities, doubtless are due to factors other than genetic racial differences, such as different modes of living, commerce, etc. The work of the last two years calls for a reconsideration of this idea. Frost in his valuable work found that “in the seven localities with considerable colored population the incidence rates among the colored were uniformly lower than among the whites, the difference persisting after adjustment of the rate to a uniform basis of sex and age distribution. The extent of the difference varied, being relatively great in Baltimore, Augusta and Louisville, and very small in Little Rock. This relatively low incidence in the colored race is quite contrary to what would have been expected a priori, in view of the fact that the death rate from pneumonia and influenza is normally higher in the colored than in the white, and that the colored population lived generally under conditions presumably more favorable to the spread of contact infection.”