In the last twelve months, 216 pairs of paiatine tonsils were removed in the Ear, Nose and Throat Department of Manchester Royal Infirmary. These operations were usually in children, from whom adenoid tissue (the pharyngeal tonsil) was removed at the same time. In the absence of a special reason, neither tonsils nor adenoids from children find their way to the surgical histology department: this is true enough to require special requests for specimens so that other people can see these organs. Adult tonsils are, of course, different in this respect.The age and sex distribution of tonsillectomy for the last four years is shown in Table I, and is remarkable for the high figure for males in the first two five-year periods and for females in the 10-25 year age group. The figures for the four-year totals of females are highly significant, and in fact the female preponderance in the adolescent and young adult groups brings-the total figures up to a near-equal distribution for the sexes, in spite of the early male preponderance. Very few tonsils are removed in Manchester Royal Infirmary before the age of 4, and hence the male period of risk appears to be 3-9 years of age and that of females 10-25 years.