360 



GROWTH 



TABLE LXXI. 



From these results we see that the agreement between observed 

 and calculated results is excellent in all cases where a sufficiently 

 large number of subjects have been weighed, except at age 15|, 

 where weight increases more rapidly than theory demands. 



A simple but empirical formula for obtaining '' expected ' 



weight is , where A = conceptional age in years and m is a 



4 -75m 



constant for each age (see Table LXXII. for values of m and for 

 results). 



(b) Length. It was at first believed that the length curve was 

 of parabolic form of the equation y 2 =a(sc+b), but later and more 

 complete investigation has shown that this is untenable. There 

 is for each type of body a definite relationship between length and 

 weight, viz. : 1= ^Jmw, where I = length in metres, w = weight in 

 kilograms, and m is a constant for each age (and each type). As 



r\ t 



A 



w = 



4 -75m 



, therefore A =4-75 / 3 or / = 



4-75 



(Pfaundler.) 



Pfaundler gives the following examples : 



(i) A boy aged 1 year has a conceptional age .4 = l-75yr. 



3 /I -75 

 Hence length = / */j-^ = V / 0-36 = 0-72 metre, which compares favourably 



with the value given in Table LXXII. 

 (ii) A boy aged 8 yrs. has A = 8-75. 



3 /fT-TR 



Hence length = '|-^ = \/l-74= 1-23 metres. 

 (Average length of boy of 8 yrs. = 1-20 metres.) 



