GROWTH. 47 



If we consider the same character of data with our laboratory girls 

 as with our boys, as plotted on figure 8, we see that the sketched line 

 indicating the trend is in general form not unlike that obtaining for 

 boys. Here again we have added the curve representing our private- 

 school girls, 1 which shows, as in the case of boys, a line measurably 

 higher at all points than the corresponding line for our laboratory 

 girls. In other words, the private-school girls are on the average 

 somewhat lighter in weight for the same height than are our girls. 



This particular phenomenon with private-school children attracts 

 especial attention here, since in all of our earlier comparisons on the 

 charts indicating the ratios of height to age and weight to age it 

 appears as if the private-school children enjoy a very marked superi- 

 ority. They are taller for the same age and heavier for the same age. 

 When, however, we compare the height to weight irrespective of age, 

 we find that our laboratory children of both sexes are slightly heavier 

 for the same height than are our private-school children. Thus the 

 seeming superiority of the private-school children may to a large 

 extent be questioned as not truly so great as at first sight appears. 

 Our analysis has not been carried out far enough to prove whether or 

 not there is a natural relationship between weight and height and 

 children are heavier because they are taller. But when we consider 

 the general configuration of children as a whole, we find that our labor- 

 atory children, both boys and girls, are somewhat heavier for the same 

 height than are the private-school children; on this basis, therefore, 

 it would appear that our laboratory children of both sexes are some- 

 what superior to the private-school children. 



From the critical examination of all these data it seems clear that 

 our laboratory children, representative as they are of the institution 

 rather than the select home, are on the whole fully up to the best 

 American standards based upon large series of individuals. The 

 striking superiority in height to age and weight to age of our private- 

 school children is in part at the sacrifice of what is commonly considered 

 the most advantageous relationship between height and weight. 



GROWTH. 



The factors determining the height and weight are so subtle, espe- 

 cially during the years of adolescence, that they probably will require 

 final analysis by the biometrician, but for this analysis to be effective 

 there should be a very much larger mass of data at hand than we now 

 possess. Under the circumstances, therefore, we can best secure an 

 indication of the general trend of the relationships between these 



1 This curve for our private-school girls should properly begin at 26 kg., as the data below 26 kg. 

 are rather limited. Nevertheless, the curve is projected below 26 kg. to 16 kg., and for this 

 section of the curve a different style of line has been used to show that the data are, strictly 

 speaking, insufficient between 16 and 26 kg. 



