70 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



from a large public school, especially in our big cities, may represent a 

 large percentage of foreign blood. Under these conditions an average 

 figure may certainly be obtained, but we believe it is not justifiable 

 to consider this average figure as normal. From the consideration of 

 the charts in which our private-school data were plotted (figs. 4 and 6), 

 it is clear that the private-school children on the whole are considerably 

 taller for their age than are our laboratory children, or, indeed, the 

 extensive series we quote from other writers. In other words, it 

 seems evident that the conditions obtaining with the children of private 

 schools in eastern Massachusetts produce a greater skeletal growth, as 

 indicated by the height. On this basis, all of these private-school 

 children are supernormal; in other words, they are certainly above 

 the average, and the question immediately arises, "Is the average to 

 be considered as normal?" 



If one objects to the values found with the private-school children 

 as normal values, no exception can be taken to the expression "ideal 

 value." Hence one should compare the height and weight of a child 

 not with the average or the fictitious normal, but with the ideal, which 

 is unquestionably represented more nearly by our data from private 

 schools. We wish here especially to emphasize the difference between 

 average, normal, and ideal. When a child is short for his age this 

 instantly indicates one of two things. In the first place, the child 

 may be the offspring of a race of people or of parents of normally 

 short stature; secondly, there may be a serious deficiency in the 

 growth-producing factors in the diet. This deficiency in growth- 

 producing factors is to be sharply distinguished from the caloric con- 

 tent of the diet, for it has been shown, with animals at least, that when 

 they are maintained upon a diet of constant caloric value during the 

 active period of growth, skeletal growth is made at the expense of the 

 addition of tissue. 



We should no longer, then, compare the height of our children to the 

 average and call this normal. The fact that a group of 800 private- 

 school children may attain a height for age considerably above that 

 of the average or so-called "normal" can be taken only as an index of 

 the fact that this average represents children living under conditions 

 which do not produce the best growth. In any educational campaign 

 for the promotion of child welfare it is important to lay special stress 

 upon those conditions favoring the largest skeletal growth. Conse- 

 quently we believe that all previous charts indicating height for age 

 are not ideal and represent simply a group of the population that has 

 been stunted, in part at least, by abnormal living conditions and 

 perhaps deficient dietary constituents. In laying down this thesis we 

 are, of course, open to the criticisms that our private-school children 

 were less contaminated by racial commingling and that the shorter 

 statured people did not send their children to these private schools- 



