The Growth of the Body in Man. 



173 



expressed in per cent, of the total number of observations. The actual 

 values are in good agreement with the theoretical requirement. 



Table XIII.— Distribution of Errors. 





Theoretical 

 distribution. 

 Percentage of 

 observations. 



Distribution for 

 individual boys. 

 Percentage of 

 observations. 



Distribution for 

 individual girls. 

 Percentage of 

 observations. 



Falling within '5 mean deviation ... 



38 3 



43 -5 



45 -3 



1-0 



68 -3 



70 -7 



77 -9 



15 



86 -6 



85 -7 



87 -2 



20 



95 4 



95 -9 



93 -0 



3-0 



99 -7 



100-0 



100 -o 



4-0 



99 -99 



100 



100 -o 



The mean deviation for boys is 3 - 378. 

 The mean deviation for girls is 4 '149. 



The mean deviation for the girls is about 4 - 2 per cent. That for boys is 

 less, but the girls cover a much wider range in weight than the boys. 

 Taking the worse figure, namely, 4% we may at any rate conclude that if 

 the body-length of an individual deviates by as much as 12 per cent, from 

 the theoretical value calculated from the body-weight by means of the 

 appropriate formula the individual is probably abnormal, and that if the 

 deviation reaches 17 per cent, the individual is certainly abnormal. 



Conclusions. 



1. Throughout the period of growth from birth to adult age the relation- 

 ship between the body-weight and body-length (stem-length) in Man conforms 

 to the formula I = kW n . 



2. In the male the value of n (to two places of decimals) is - 33, in the 

 female it is - 32. 



3. The value of the length constant h as determined for grouped 

 individuals is 23 - 23 for males and 25 - 60 for females. For the individual 

 boy its average value is 23'33, and for the individual girl 25'58. 



4. If the body-length of an individual differ by as much as 17 per cent, 

 from the value calculated by means of the appropriate formula the individual 

 is certainly abnormal ; if it differs by 12 per cent, it is probably abnormal. 



The relationship between height and weight, and between height and length, 

 is at present under investigation. 



