CORRELATED VARIABILITY. 35 



*) = 1142-9 9+1652 ^ 

 2(fX,) + Sr(f) 5125 



= 4- 806 + 814 + 829 ^ -*- = - = 2.5625 

 .) - 2m(fX l ) 



= _ 49 - 51 J 



- S,, = -4535 X. 4605= 



= 1.7195 X 1.7304 = 2.9754; p = = .7919 



1/2000 X 1.627 



SPURIOUS CORRELATION IN INDICES. 



When two characters A and B are measured in each individual 

 ofaseries of individuals, and each absolute magnitude is trans- 

 formed into an index by dividing it by the magnitude of a 

 third character C as found in the same individual, a spurious 

 correlation will be found to exist between the indices of 

 A . B 



c and c 



Let Vi = the coefficient of variation of A ; 



o a = B; 



PO " " spurious correlation. 



The precise method of using p Q in modifying any determina- 

 tion of p is uncertain. Pearson recommends using p p as 

 the true measure of "organic correlation" in the case of 

 indices. 



HEREDITY. 



Heredity is a certain degree of correlation between the 

 abmodality of parent and offspring. The statistical laws of 

 heredity deal not with relations between one descendant and 



