62 American Statistical Association. 



considerably longer in heiglit sitting than in any other 

 dimension. 



Big girls begin to be larger than l)ig boys at an earlier age 

 than that at which small girls begin to exceed small boys. 

 The period in which small girls are larger than small boys is 

 longer than that in which big girls are larger than big boys. 



The absolute annual increase of height standing, weight, 

 span of arms, height sitting, girth of chest, and strength of 

 squeeze is greatest in girls at age 13, and in boys at age 15, 

 nearest birthday. The relative annual increase (increase at 

 any year divided by the average value at that year) gives a 

 truer idea of growth than the absolute annual increase, 

 because the latter value is entangled with the size of the indi- 

 vidual measured. The absolute increase is commonly greater 

 in a big boy than in a small boy, and yet the rate of growth 

 may be the same. The relative annual increase is free of 

 such errors. The relative annual increase in strength of 

 squeeze, weight, height standing, height sitting, span of arras, 

 and girth of chest is treated in Chapter VII of The Groiotli 

 of St. Louis Children. 



The ratio of span of arms, height sitting, chest girth, 

 weight, strength of squeeze with right hand, and five head 

 and face measurements to height standing is also given in 

 Chapter VII. These relations are shown graphicall}^ in Plate 

 XL V of Growth of St. Louis Children., height standing being 

 expressed by an abscissa, and the percentage relation of the 

 other dimensions to height displayed in curves. Of all these, 

 span of arms most closely approximates the height, the differ- 

 ence being less than one per cent of the latter from age 6 to 

 11, and scarcely more than two per cent in subsequent ages. 

 The heiglit sitting and the girth of chest run a parallel course, 

 and are, moreover, nearly equal, the girth of chest being about 

 two per cent less than the height sitting. They increase a 

 little less rapidly than the height, showing a decline of about 

 4 per cent in thirteen years. Height sitting and chest girth 

 are not far from half the height standing. 



