ONTOGENETIC CURVE OF Hill.]). 



1 1 



6. Schmid-Monnard ( 1892 1 data. Copied from Bardeen (1920, page 



5421. Boys and girls measured at Frankfort am Mam. Germany. 8 U I i 

 in respective months. Ages 1 to 13 months and up to .'*<) months. 



7. Crum (1915) data. Average measurements of babies without regard 

 to sex, 193 to 264 per month, mostly baby-show babies and hence Btrongly 

 selected. Various parts of the United States. 



From the foregoing collections of data, tables 3, 4, and 5 were drawn 

 up, giving for each age the mean relative chest-girth found by each 

 observer. Also, the number of individuals upon which the measure- 

 ment is based, necessary for weighting the mean. The mean of all 

 measurements was weighted in table 4, but not in table 3 for the 

 reasons stated on page 8. 



Table 4. — Average relative chest-girth of irifants from birth to 13 month*. 



[Obtained from 6 series of observations, described on pages 12, 13. The main entries of the tabic 

 are given in 4 places of decimals (point omitted). Immediately to the loft of each main entry i« 

 given the number of persons measured to obtain that average. The column at the extreme right 

 gives the weighted averages of the averages standing in the same line.] 



It will be observed that the means of build differ, for the constant 

 age, more than do the differences between successive ages. That is to 

 say, the absolute difference between races at any given age is greater 

 than the average differences between one year and the next. 



The mean relative chest circumferences for the different ages are 

 plotted in figure 2. 



The Ontogenetic Cubvb oi Hi ild. 



The resulting curve of build from birth to maturity is given in 

 figure 1. This curve shows that build in males is greatest at birth, 

 or at about 1 month, and that it then steadily diminishes to L2 years 



