106 



THE RATE OF GROWTH 



[CH. 



steadily, and the lad of sixteen is some 15 per cent, heavier than 

 the lass. The disparity tends to diminish for a while, when the 

 maid of seventeen has her second spurt of growth ; but it increases 

 again, though slowly, until at five-and-twenty the young woman is 

 no more than four-fifths the weight of the man. During middle life 

 she gains on him, and at sixty the difference stands at some 12 



1 1 \ r 



J i \ \ \ \ L 



2 4 6 8 10 12 14 16 18 



Age 



Fig. 12. Annual increments of stature, in boys and girls. 

 From Quetelet's data. (Smoothed curves.) 



per cent., not far from the mean for all ages; but the old woman 

 shrinks and dwindles, and the difference tends to increase again. 



The rate of increase of stature, like stature itself, differs notably 

 in the two sexes, and the differences, as in the case of weight, are 

 mostly a question of phase (Fig. 12). The httle girl is adding rather 

 more to her stature than the boy at four years old*, but she grows 



* This early spurt of growth in the girl is shewn in Enghsh, French and American 

 observations, but not in Quetelet's. 



