Increment Age Male Female 0–1 5·9 5·6 1–2 2·0 2·4 2–3 1·5 1·4 3–4 1·5 1·5 4–5 1·9 1·4 5–6 1·9 1·4 6–7 1·9 1·1 7–8 1·9 1·2 8–9 1·9 2·0 9–10 1·7 2·1 10–11 1·8 2·4 11–12 2·0 3·5 12–13 4·1 3·5 13–14 4·0 3·8 14–15 4·1 3·7 15–16 4·2 3·5 16–17 4·3 3·3 17–18 4·2 3·0 18–19 3·7 2·3 19–20 1·9 1·1 20–21 1·7 1·1 21–22 1·7 0·5 22–23 1·6 0·4 23–24 0·9 −0·2 24–25 0·8 −0·2 * The values given in this table are not in precise accord with those of the Table on p. 63. The latter represent Quetelet’s results arrived at in 1835; the former are the means of his determinations in 1835–40. The acceleration-curve for man’s weight (Fig. 5), whether we draw it from Quetelet’s data, or from the British, American and other statistics of later writers, is on the whole similar to that which we deduce from the statistics of these latter writers in regard to height or stature; that is to say, it is not a curve which continually descends, but it indicates a rate of growth which is subject to important fluctuations at certain epochs of life. We see that it begins at a high level, and falls continuously and rapidly[100] {69} during the first two or three years of life. After a slight recovery, it runs nearly level during boyhood from about five to twelve years old; it then rapidly rises, in the “growing period” of the early teens, and slowly and steadily falls from about the age of sixteen onwards. It does not reach the base-line till the man is about seven or eight and twenty, for normal increase of weight continues during the years when the man is “filling out,” long after growth in height has ceased; but at last, somewhere about thirty, the velocity reaches zero, and even falls below it, for then the man usually begins to lose weight a little. The subsequent slow changes in this acceleration-curve we need not stop to deal with. [Illustration: Fig. 5. Mean annual increments of weight, in man and woman; from Quetelet’s data.]