_Relationship of age._—Leichtenstern has summarized the results for the epidemic of thirty years ago, in saying that the death rate for children under one year was little disturbed by the influenza epidemic; that there was very little increase in mortality in the other ages of childhood; that the higher age periods showed the greatest relative mortality for the disease. On the contrary, the records for England and for Switzerland showed during those periods a higher death rate in children up to five years of age. Percentages. Ages. 1847–8 1890 1–5 10.5 5.2 5–20 13.1 4.3 20–40 3.8 4.7 40–60 18.5 36.2 60–80 16.9 22.4 Above 80 8.6 2.5 Giltay has compared the age mortality in Amsterdam in 1890, 1900 and 1918 as shown in the following table: ═══════╤═══════╤═══════╤═══════╤═══════╤═══════╤═══════╤═══════╤═══════ │ Under │ │ │ │ │ │ │ │ one │ 1–4 │ 5–13 │ 14–19 │ 20–49 │ 50–64 │Over 64│Total. │ year. │ │ │ │ │ │ │ ───────┼───────┼───────┼───────┼───────┼───────┼───────┼───────┼─────── 1890│ 8.4│ 8.1│ 2.3│ 3.0│ 30.7│ 19.3│ 28.1│ 100 1900│ 9.7│ 8.8│ 1.6│ 3.2│ 17.6│ 18.3│ 40.8│ 100 1918│ 3.0│ 13.0│ 8.7│ 8.3│ 51.9│ 8.7│ 6.4│ 100 ───────┴───────┴───────┴───────┴───────┴───────┴───────┴───────┴─────── Evans has studied the records for the city of Chicago in the epidemic of the year 1890, and found that the number of deaths was highest among persons from 20 to 40 years of age. The greater increase above the expected was in deaths of persons over 60 years of age. Children of school age seemed to enjoy some relative immunity, as shown in the mortality reports. This latter age grouping for 30 years ago corresponds with those of 1918. Frost found that the death rate per 1,000 was notably high in children under one year of age, in adults from 20 to 40, and in persons over 60. The case fatality from pneumonia in his series tended to be fairly constant, around 30 per cent., except in San Antonio, Texas, where it was only 18.5 per cent. Case fatality was also higher in the following age groups: Under one year, 20 to 40, and over sixty.