Anthropological Measurements of Children. 31 



It has been shown in the foregoing pages that the means 

 derived from anthropometrical measurements l)y the general- 

 izing method can be used to determine whether the weight 

 and other physical dimensions of an individual are normal in 

 relation to lieight, and it has been i)ointe(l out that tliis nor- 

 mal relation constitutes the health of the individual. It fol- 

 lows that the normal amount of labor cannot be exacted 

 without injury from those in whom this normal equilibrium 

 is wanting. These facts must therefore be taken into account 

 in a rational school system, and it should now be made phiin 

 how this is to be done. 



II. 



All systems of education have for their object the largest 

 possible development of individual minds. In large schools 

 the tasks by which this development is promoted are those 

 which secure from the child of mean ability its maximum 

 mental output. In practice they are determined by examina- 

 tions. Hence the existence in every educational institution 

 uf classes or grades based on the mental output of the mean 

 pupil, and related to age only in that the output fixed as the 

 standard of any class is necessarily found more often at a cer- 

 tain age than at other ages. Thus there exists a mean age 

 for each class, the greater number of pupils at anv age being- 

 found in the same class, while some have advanced beyond, 

 and others, equally old, have not yet come so far as tlifti class. 



On an average, those who have advanced beyond the 

 greater number of their age are precocious, that is, possess 

 more than the mean capacity for mental labor, while those 

 who are less advanced are dull, possessing less than the mean 

 capacity. It has been detnonstrated that there is a physical 

 basis for precocity and dullness.* When numbers sufficiently 

 large for safe statistical work are employed, it is seen that 

 precocious pupils possess a greater mean weight, height, etc. 

 than the mean pupils, and that the latter are heavier and 



* W. Townsend Porter, loc. cit. 



